Bump actions/labeler from 4 to 5

Bumps [actions/labeler](https://github.com/actions/labeler) from 4 to 5.
- [Release notes](https://github.com/actions/labeler/releases)
- [Commits](https://github.com/actions/labeler/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/labeler
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.clang-format

@@ -1,30 +0,0 @@
-BasedOnStyle: LLVM
-IndentWidth: 4
-BreakBeforeBraces: Custom
-BraceWrapping:
-  AfterStruct: true
-  AfterClass: true
-  AfterFunction: true
-  AfterUnion: true
-  SplitEmptyRecord: false
-PointerAlignment: Middle
-FixNamespaceComments: false
-SortIncludes: Never
-#IndentPPDirectives: BeforeHash
-SpaceAfterCStyleCast: true
-SpaceAfterTemplateKeyword: false
-AccessModifierOffset: -4
-AlignAfterOpenBracket: AlwaysBreak
-AlignEscapedNewlines: DontAlign
-ColumnLimit: 120
-BreakStringLiterals: false
-BitFieldColonSpacing: None
-AllowShortFunctionsOnASingleLine: Empty
-AlwaysBreakTemplateDeclarations: Yes
-BinPackParameters: false
-BreakConstructorInitializers: BeforeComma
-EmptyLineAfterAccessModifier: Leave # change to always/never later?
-EmptyLineBeforeAccessModifier: Leave
-#PackConstructorInitializers: BinPack
-BreakBeforeBinaryOperators: NonAssignment
-AlwaysBreakBeforeMultilineStrings: true

.github/workflows/labels.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository_owner == 'NixOS'
     steps:
-    - uses: actions/labeler@v4
+    - uses: actions/labeler@v5
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         sync-labels: false

.gitignore

@@ -21,14 +21,12 @@ perl/Makefile.config
 /doc/manual/language.json
 /doc/manual/xp-features.json
 /doc/manual/src/SUMMARY.md
-/doc/manual/src/SUMMARY-rl-next.md
 /doc/manual/src/command-ref/new-cli
 /doc/manual/src/command-ref/conf-file.md
 /doc/manual/src/command-ref/experimental-features-shortlist.md
 /doc/manual/src/contributing/experimental-feature-descriptions.md
 /doc/manual/src/language/builtins.md
 /doc/manual/src/language/builtin-constants.md
-/doc/manual/src/release-notes/rl-next.md
 
 # /scripts/
 /scripts/nix-profile.sh
@@ -43,16 +41,13 @@ perl/Makefile.config
 /src/libexpr/parser-tab.hh
 /src/libexpr/parser-tab.output
 /src/libexpr/nix.tbl
-/src/libexpr/tests
 /tests/unit/libexpr/libnixexpr-tests
 
 # /src/libstore/
 *.gen.*
-/src/libstore/tests
 /tests/unit/libstore/libnixstore-tests
 
 # /src/libutil/
-/src/libutil/tests
 /tests/unit/libutil/libnixutil-tests
 
 /src/nix/nix
@@ -95,7 +90,6 @@ perl/Makefile.config
 /tests/functional/ca/config.nix
 /tests/functional/dyn-drv/config.nix
 /tests/functional/repl-result-out
-/tests/functional/debugger-test-out
 /tests/functional/test-libstoreconsumer/test-libstoreconsumer
 
 # /tests/functional/lang/
@@ -143,12 +137,8 @@ compile_commands.json
 nix-rust/target
 
 result
-result-*
 
 .vscode/
 
 # clangd and possibly more
 .cache/
-
-# Mac OS
-.DS_Store

.version

@@ -1 +1 @@
-2.90.0
+2.18.1

Makefile

@@ -1,9 +1,3 @@
-include mk/build-dir.mk
-
--include $(buildprefix)Makefile.config
-clean-files += $(buildprefix)Makefile.config
-
-ifeq ($(ENABLE_BUILD), yes)
 makefiles = \
   mk/precompiled-headers.mk \
   local.mk \
@@ -21,19 +15,17 @@ makefiles = \
   misc/zsh/local.mk \
   misc/systemd/local.mk \
   misc/launchd/local.mk \
-  misc/upstart/local.mk
-endif
+  misc/upstart/local.mk \
+  doc/manual/local.mk \
+  doc/internal-api/local.mk
 
-ifeq ($(ENABLE_BUILD)_$(ENABLE_TESTS), yes_yes)
-UNIT_TEST_ENV = _NIX_TEST_UNIT_DATA=unit-test-data
+-include Makefile.config
+
+ifeq ($(tests), yes)
 makefiles += \
   tests/unit/libutil/local.mk \
   tests/unit/libutil-support/local.mk \
-  tests/unit/libstore/local.mk
-endif
-
-ifeq ($(ENABLE_TESTS), yes)
-makefiles += \
+  tests/unit/libstore/local.mk \
   tests/unit/libstore-support/local.mk \
   tests/unit/libexpr/local.mk \
   tests/unit/libexpr-support/local.mk \
@@ -41,23 +33,12 @@ makefiles += \
   tests/functional/ca/local.mk \
   tests/functional/dyn-drv/local.mk \
   tests/functional/test-libstoreconsumer/local.mk \
-  tests/functional/repl_characterization/local.mk \
   tests/functional/plugins/local.mk
 else
 makefiles += \
   mk/disable-tests.mk
 endif
 
-# Some makefiles require access to built programs and must be included late.
-makefiles-late =
-
-ifeq ($(ENABLE_BUILD), yes)
-makefiles-late += doc/manual/local.mk
-makefiles-late += doc/internal-api/local.mk
-endif
-
-# Miscellaneous global Flags
-
 OPTIMIZE = 1
 
 ifeq ($(OPTIMIZE), 1)
@@ -69,4 +50,4 @@ endif
 
 include mk/lib.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -Wimplicit-fallthrough -include $(buildprefix)config.h -std=c++2a -I src
+GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++2a -I src

Makefile.config.in

@@ -46,6 +46,5 @@ sandbox_shell = @sandbox_shell@
 storedir = @storedir@
 sysconfdir = @sysconfdir@
 system = @system@
-ENABLE_BUILD = @ENABLE_BUILD@
-ENABLE_TESTS = @ENABLE_TESTS@
+tests = @tests@
 internal_api_docs = @internal_api_docs@

boehmgc-coroutine-sp-fallback.diff

@@ -59,18 +59,12 @@ index b5d71e62..aed7b0bf 100644
      GC_bool found_me = FALSE;
      size_t nthreads = 0;
      int i;
-@@ -851,6 +853,37 @@ GC_INNER void GC_push_all_stacks(void)
+@@ -851,6 +853,31 @@ GC_INNER void GC_push_all_stacks(void)
            hi = p->altstack + p->altstack_size;
            /* FIXME: Need to scan the normal stack too, but how ? */
            /* FIXME: Assume stack grows down */
 +        } else {
-+#ifdef HAVE_PTHREAD_ATTR_GET_NP
-+          if (!pthread_attr_init(&pattr)
-+              || !pthread_attr_get_np(p->id, &pattr))
-+#else /* HAVE_PTHREAD_GETATTR_NP */
-+          if (pthread_getattr_np(p->id, &pattr))
-+#endif
-+          {
++          if (pthread_getattr_np(p->id, &pattr)) {
 +            ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
 +          }
 +          if (pthread_attr_getstacksize(&pattr, &stack_limit)) {

boehmgc-traceable_allocator-public.diff

@@ -1,12 +0,0 @@
-diff --git a/include/gc_allocator.h b/include/gc_allocator.h
-index 597c7f13..587286be 100644
---- a/include/gc_allocator.h
-+++ b/include/gc_allocator.h
-@@ -312,6 +312,7 @@ public:
- 
- template<>
- class traceable_allocator<void> {
-+public:
-   typedef size_t      size_type;
-   typedef ptrdiff_t   difference_type;
-   typedef void*       pointer;

bootstrap.sh

@@ -0,0 +1,4 @@
+#! /bin/sh -e
+rm -f aclocal.m4
+mkdir -p config
+exec autoreconf -vfi

configure.ac

@@ -47,10 +47,6 @@ AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier ('cpu-os')])
 # State should be stored in /nix/var, unless the user overrides it explicitly.
 test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var
 
-# Assign a default value to C{,XX}FLAGS as the default configure script sets them
-# to -O2 otherwise, which we don't want to have hardcoded
-CFLAGS=${CFLAGS-""}
-CXXFLAGS=${CXXFLAGS-""}
 
 AC_PROG_CC
 AC_PROG_CXX
@@ -72,9 +68,6 @@ case "$host_os" in
 esac
 
 
-ENSURE_NO_GCC_BUG_80431
-
-
 # Check for pubsetbuf.
 AC_MSG_CHECKING([for pubsetbuf])
 AC_LANG_PUSH(C++)
@@ -159,17 +152,12 @@ if test "x$GCC_ATOMIC_BUILTINS_NEED_LIBATOMIC" = xyes; then
     LDFLAGS="-latomic $LDFLAGS"
 fi
 
-# Running the functional tests without building Nix is useful for testing
-# different pre-built versions of Nix against each other.
-AC_ARG_ENABLE(build, AS_HELP_STRING([--disable-build],[Do not build nix]),
-  ENABLE_BUILD=$enableval, ENABLE_BUILD=yes)
-AC_SUBST(ENABLE_BUILD)
 # Building without tests is useful for bootstrapping with a smaller footprint
 # or running the tests in a separate derivation. Otherwise, we do compile and
 # run them.
 AC_ARG_ENABLE(tests, AS_HELP_STRING([--disable-tests],[Do not build the tests]),
-  ENABLE_TESTS=$enableval, ENABLE_TESTS=yes)
-AC_SUBST(ENABLE_TESTS)
+  tests=$enableval, tests=yes)
+AC_SUBST(tests)
 
 # Building without API docs is the default as Nix' C++ interfaces are internal and unstable.
 AC_ARG_ENABLE(internal_api_docs, AS_HELP_STRING([--enable-internal-api-docs],[Build API docs for Nix's internal unstable C++ interfaces]),
@@ -301,10 +289,10 @@ if test "$gc" = yes; then
 fi
 
 
-if test "$ENABLE_TESTS" = yes; then
+if test "$tests" = yes; then
 
 # Look for gtest.
-PKG_CHECK_MODULES([GTEST], [gtest_main gmock_main])
+PKG_CHECK_MODULES([GTEST], [gtest_main])
 
 
 # Look for rapidcheck.

doc/internal-api/doxygen.cfg.in

@@ -58,23 +58,6 @@ INPUT                  = \
   src/nix-env \
   src/nix-store
 
-# If the MACRO_EXPANSION tag is set to YES, doxygen will expand all macro names
-# in the source code. If set to NO, only conditional compilation will be
-# performed. Macro expansion can be done in a controlled way by setting
-# EXPAND_ONLY_PREDEF to YES.
-# The default value is: NO.
-# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
-
-MACRO_EXPANSION        = YES
-
-# If the EXPAND_ONLY_PREDEF and MACRO_EXPANSION tags are both set to YES then
-# the macro expansion is limited to the macros specified with the PREDEFINED and
-# EXPAND_AS_DEFINED tags.
-# The default value is: NO.
-# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
-
-EXPAND_ONLY_PREDEF     = YES
-
 # The INCLUDE_PATH tag can be used to specify one or more directories that
 # contain include files that are not input files but should be processed by the
 # preprocessor. Note that the INCLUDE_PATH is not recursive, so the setting of
@@ -82,16 +65,3 @@ EXPAND_ONLY_PREDEF     = YES
 # This tag requires that the tag SEARCH_INCLUDES is set to YES.
 
 INCLUDE_PATH           = @RAPIDCHECK_HEADERS@
-
-# If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
-# tag can be used to specify a list of macro names that should be expanded. The
-# macro definition that is found in the sources will be used. Use the PREDEFINED
-# tag if you want to use a different macro definition that overrules the
-# definition found in the source code.
-# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
-
-EXPAND_AS_DEFINED      = \
-  DECLARE_COMMON_SERIALISER \
-  DECLARE_WORKER_SERIALISER \
-  DECLARE_SERVE_SERIALISER \
-  LENGTH_PREFIXED_PROTO_HELPER

doc/manual/generate-manpage.nix

@@ -70,7 +70,6 @@ let
         * [`${command} ${name}`](./${appendName filename name}.md) - ${subcmd.description}
       '';
 
-      # TODO: move this confusing special case out of here when implementing #8496
       maybeStoreDocs = optionalString
         (details ? doc)
         (replaceStrings ["@stores@"] [storeDocs] details.doc);
@@ -79,10 +78,6 @@ let
         # Options
 
         ${showOptions details.flags toplevel.flags}
-
-        > **Note**
-        >
-        > See [`man nix.conf`](@docroot@/command-ref/conf-file.md#command-line-flags) for overriding configuration settings with command line flags.
       '';
 
       showOptions = options: commonOptions:
@@ -155,7 +150,7 @@ let
             To use this store, you need to make sure the corresponding experimental feature,
             [`${experimentalFeature}`](@docroot@/contributing/experimental-features.md#xp-feature-${experimentalFeature}),
             is enabled.
-            For example, include the following in [`nix.conf`](@docroot@/command-ref/conf-file.md):
+            For example, include the following in [`nix.conf`](#):
 
             ```
             extra-experimental-features = ${experimentalFeature}

doc/manual/local.mk

@@ -1,10 +1,5 @@
 ifeq ($(doc_generate),yes)
 
-# The version of Nix used to generate the doc. Can also be
-# `$(nix_INSTALL_PATH)` or just `nix` (to grap ambient from the `PATH`),
-# if one prefers.
-doc_nix = $(nix_PATH)
-
 MANUAL_SRCS := \
 	$(call rwildcard, $(d)/src, *.md) \
 	$(call rwildcard, $(d)/src, */*.md)
@@ -37,7 +32,7 @@ dummy-env = env -i \
 	NIX_STATE_DIR=/dummy \
 	NIX_CONFIG='cores = 0'
 
-nix-eval = $(dummy-env) $(doc_nix) eval --experimental-features nix-command -I nix/corepkgs=corepkgs --store dummy:// --impure --raw
+nix-eval = $(dummy-env) $(bindir)/nix eval --experimental-features nix-command -I nix/corepkgs=corepkgs --store dummy:// --impure --raw
 
 # re-implement mdBook's include directive to make it usable for terminal output and for proper @docroot@ substitution
 define process-includes
@@ -97,76 +92,58 @@ $(d)/nix-profiles.5: $(d)/src/command-ref/files/profiles.md
 	$(trace-gen) lowdown -sT man --nroff-nolinks -M section=5 $^.tmp -o $@
 	@rm $^.tmp
 
-$(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/SUMMARY-rl-next.md $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md
+$(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md
 	@cp $< $@
 	@$(call process-includes,$@,$@)
 
-$(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/utils.nix $(d)/generate-manpage.nix $(doc_nix)
+$(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/utils.nix $(d)/generate-manpage.nix $(bindir)/nix
 	@rm -rf $@ $@.tmp
 	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-manpage.nix true (builtins.readFile $<)'
 	@mv $@.tmp $@
 
-$(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/utils.nix $(d)/src/command-ref/conf-file-prefix.md $(d)/src/command-ref/experimental-features-shortlist.md $(doc_nix)
+$(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/utils.nix $(d)/src/command-ref/conf-file-prefix.md $(d)/src/command-ref/experimental-features-shortlist.md $(bindir)/nix
 	@cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp
 	$(trace-gen) $(nix-eval) --expr '(import doc/manual/utils.nix).showSettings { inlineHTML = true; } (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp;
 	@mv $@.tmp $@
 
-$(d)/nix.json: $(doc_nix)
-	$(trace-gen) $(dummy-env) $(doc_nix) __dump-cli > $@.tmp
+$(d)/nix.json: $(bindir)/nix
+	$(trace-gen) $(dummy-env) $(bindir)/nix __dump-cli > $@.tmp
 	@mv $@.tmp $@
 
-$(d)/conf-file.json: $(doc_nix)
-	$(trace-gen) $(dummy-env) $(doc_nix) show-config --json --experimental-features nix-command > $@.tmp
+$(d)/conf-file.json: $(bindir)/nix
+	$(trace-gen) $(dummy-env) $(bindir)/nix show-config --json --experimental-features nix-command > $@.tmp
 	@mv $@.tmp $@
 
-$(d)/src/contributing/experimental-feature-descriptions.md: $(d)/xp-features.json $(d)/utils.nix $(d)/generate-xp-features.nix $(doc_nix)
+$(d)/src/contributing/experimental-feature-descriptions.md: $(d)/xp-features.json $(d)/utils.nix $(d)/generate-xp-features.nix $(bindir)/nix
 	@rm -rf $@ $@.tmp
 	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-xp-features.nix (builtins.fromJSON (builtins.readFile $<))'
 	@mv $@.tmp $@
 
-$(d)/src/command-ref/experimental-features-shortlist.md: $(d)/xp-features.json $(d)/utils.nix $(d)/generate-xp-features-shortlist.nix $(doc_nix)
+$(d)/src/command-ref/experimental-features-shortlist.md: $(d)/xp-features.json $(d)/utils.nix $(d)/generate-xp-features-shortlist.nix $(bindir)/nix
 	@rm -rf $@ $@.tmp
 	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-xp-features-shortlist.nix (builtins.fromJSON (builtins.readFile $<))'
 	@mv $@.tmp $@
 
-$(d)/xp-features.json: $(doc_nix)
-	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(doc_nix) __dump-xp-features > $@.tmp
+$(d)/xp-features.json: $(bindir)/nix
+	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(bindir)/nix __dump-xp-features > $@.tmp
 	@mv $@.tmp $@
 
-$(d)/src/language/builtins.md: $(d)/language.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(doc_nix)
+$(d)/src/language/builtins.md: $(d)/language.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(bindir)/nix
 	@cat doc/manual/src/language/builtins-prefix.md > $@.tmp
 	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<)).builtins' >> $@.tmp;
 	@cat doc/manual/src/language/builtins-suffix.md >> $@.tmp
 	@mv $@.tmp $@
 
-$(d)/src/language/builtin-constants.md: $(d)/language.json $(d)/generate-builtin-constants.nix $(d)/src/language/builtin-constants-prefix.md $(doc_nix)
+$(d)/src/language/builtin-constants.md: $(d)/language.json $(d)/generate-builtin-constants.nix $(d)/src/language/builtin-constants-prefix.md $(bindir)/nix
 	@cat doc/manual/src/language/builtin-constants-prefix.md > $@.tmp
 	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtin-constants.nix (builtins.fromJSON (builtins.readFile $<)).constants' >> $@.tmp;
 	@cat doc/manual/src/language/builtin-constants-suffix.md >> $@.tmp
 	@mv $@.tmp $@
 
-$(d)/language.json: $(doc_nix)
-	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(doc_nix) __dump-language > $@.tmp
+$(d)/language.json: $(bindir)/nix
+	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(bindir)/nix __dump-language > $@.tmp
 	@mv $@.tmp $@
 
-# Generate "Upcoming release" notes (or clear it and remove from menu)
-$(d)/src/release-notes/rl-next.md: $(d)/rl-next $(d)/rl-next/*
-	@if type -p changelog-d > /dev/null; then \
-		echo "  GEN   " $@; \
-		changelog-d doc/manual/rl-next > $@; \
-	else \
-		echo "  NULL  " $@; \
-		true > $@; \
-	fi
-
-$(d)/src/SUMMARY-rl-next.md: $(d)/src/release-notes/rl-next.md
-	$(trace-gen) true
-	@if [ -s $< ]; then \
-		echo '  - [Upcoming release](release-notes/rl-next.md)' > $@; \
-	else \
-	  true > $@; \
-	fi
-
 # Generate the HTML manual.
 .PHONY: manual-html
 manual-html: $(docdir)/manual/index.html
@@ -196,7 +173,7 @@ doc/manual/generated/man1/nix3-manpages: $(d)/src/command-ref/new-cli
 	done
 	@touch $@
 
-$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/anchors.jq $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md $(d)/src/command-ref/conf-file.md $(d)/src/language/builtins.md $(d)/src/language/builtin-constants.md $(d)/src/release-notes/rl-next.md
+$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/anchors.jq $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md $(d)/src/command-ref/conf-file.md $(d)/src/language/builtins.md $(d)/src/language/builtin-constants.md
 	$(trace-gen) \
 		tmp="$$(mktemp -d)"; \
 		cp -r doc/manual "$$tmp"; \

doc/manual/rl-next/better-errors-in-nix-repl.md

@@ -1,40 +0,0 @@
----
-synopsis: Concise error printing in `nix repl`
-prs: 9928
----
-
-Previously, if an element of a list or attribute set threw an error while
-evaluating, `nix repl` would print the entire error (including source location
-information) inline. This output was clumsy and difficult to parse:
-
-```
-nix-repl> { err = builtins.throw "uh oh!"; }
-{ err = «error:
-       … while calling the 'throw' builtin
-         at «string»:1:9:
-            1| { err = builtins.throw "uh oh!"; }
-             |         ^
-
-       error: uh oh!»; }
-```
-
-Now, only the error message is displayed, making the output much more readable.
-```
-nix-repl> { err = builtins.throw "uh oh!"; }
-{ err = «error: uh oh!»; }
-```
-
-However, if the whole expression being evaluated throws an error, source
-locations and (if applicable) a stack trace are printed, just like you'd expect:
-
-```
-nix-repl> builtins.throw "uh oh!"
-error:
-       … while calling the 'throw' builtin
-         at «string»:1:1:
-            1| builtins.throw "uh oh!"
-             | ^
-
-       error: uh oh!
-```
-

doc/manual/rl-next/config

@@ -1,2 +0,0 @@
-organization: NixOS
-repository: nix

doc/manual/rl-next/debugger-locals-for-let-expressions.md

@@ -1,9 +0,0 @@
----
-synopsis: "`--debugger` can now access bindings from `let` expressions"
-prs: 9918
-issues: 8827.
----
-
-Breakpoints and errors in the bindings of a `let` expression can now access
-those bindings in the debugger. Previously, only the body of `let` expressions
-could access those bindings.

doc/manual/rl-next/debugger-on-trace.md

@@ -1,9 +0,0 @@
----
-synopsis: Enter the `--debugger` when `builtins.trace` is called if `debugger-on-trace` is set
-prs: 9914
----
-
-If the `debugger-on-trace` option is set and `--debugger` is given,
-`builtins.trace` calls will behave similarly to `builtins.break` and will enter
-the debug REPL. This is useful for determining where warnings are being emitted
-from.

doc/manual/rl-next/drv-string-parse-hang.md

@@ -1,6 +0,0 @@
----
-synopsis: Fix handling of truncated `.drv` files.
-prs: 9673
----
-
-Previously a `.drv` that was truncated in the middle of a string would case nix to enter an infinite loop, eventually exhausting all memory and crashing.

doc/manual/rl-next/empty-search-regex.md

@@ -1,8 +0,0 @@
-synopsis: Disallow empty search regex in `nix search`
-prs: #9481
-description: {
-
-[`nix search`](@docroot@/command-ref/new-cli/nix3-search.md) now requires a search regex to be passed. To show all packages, use `^`.
-
-}
-

doc/manual/rl-next/enter-debugger-more-reliably-in-let-and-calls.md

@@ -1,25 +0,0 @@
----
-synopsis: The `--debugger` will start more reliably in `let` expressions and function calls
-prs: 9917
-issues: 6649
----
-
-Previously, if you attempted to evaluate this file with the debugger:
-
-```nix
-let
-  a = builtins.trace "before inner break" (
-    builtins.break "hello"
-  );
-  b = builtins.trace "before outer break" (
-    builtins.break a
-  );
-in
-  b
-```
-
-Nix would correctly enter the debugger at `builtins.break a`, but if you asked
-it to `:continue`, it would skip over the `builtins.break "hello"` expression
-entirely.
-
-Now, Nix will correctly enter the debugger at both breakpoints.

doc/manual/rl-next/env-size-reduction.md

@@ -1,7 +0,0 @@
----
-synopsis: Reduce eval memory usage and wall time
-prs: 9658
----
-
-Reduce the size of the `Env` struct used in the evaluator by a pointer, or 8 bytes on most modern machines.
-This reduces memory usage during eval by around 2% and wall time by around 3%.

doc/manual/rl-next/eval-system.md

@@ -1,12 +0,0 @@
----
-synopsis: Add new `eval-system` setting
-prs: 4093
----
-
-Add a new `eval-system` option.
-Unlike `system`, it just overrides the value of `builtins.currentSystem`.
-This is more useful than overriding `system`, because you can build these derivations on remote builders which can work on the given system.
-In contrast, `system` also effects scheduling which will cause Nix to build those derivations locally even if that doesn't make sense.
-
-`eval-system` only takes effect if it is non-empty.
-If empty (the default) `system` is used as before, so there is no breakage.

doc/manual/rl-next/inherit-from-by-need.md

@@ -1,7 +0,0 @@
----
-synopsis: "`inherit (x) ...` evaluates `x` only once"
-prs: 9847
----
-
-`inherit (x) a b ...` now evaluates the expression `x` only once for all inherited attributes rather than once for each inherited attribute.
-This does not usually have a measurable impact, but side-effects (such as `builtins.trace`) would be duplicated and expensive expressions (such as derivations) could cause a measurable slowdown.

doc/manual/rl-next/nix-env-json-drv-path.md

@@ -1,6 +0,0 @@
----
-synopsis: Fix `nix-env --query --drv-path --json`
-prs: 9257
----
-
-Fixed a bug where `nix-env --query` ignored `--drv-path` when `--json` was set.

doc/manual/rl-next/nix-flake-check-logs-actions.md

@@ -1,33 +0,0 @@
----
-synopsis: "`nix flake check` logs the checks"
-issues: 8882
-prs: 8893
----
-
-`nix flake check` now logs the checks it runs and the derivations it evaluates:
-
-```
-$ nix flake check -v
-evaluating flake...
-checking flake output 'checks'...
-checking derivation 'checks.aarch64-darwin.ghciwatch-tests'...
-derivation evaluated to /nix/store/nh7dlvsrhds4cxl91mvgj4h5cbq6skmq-ghciwatch-test-0.3.0.drv
-checking derivation 'checks.aarch64-darwin.ghciwatch-clippy'...
-derivation evaluated to /nix/store/9cb5a6wmp6kf6hidqw9wphidvb8bshym-ghciwatch-clippy-0.3.0.drv
-checking derivation 'checks.aarch64-darwin.ghciwatch-doc'...
-derivation evaluated to /nix/store/8brdd3jbawfszpbs7vdpsrhy80as1il8-ghciwatch-doc-0.3.0.drv
-checking derivation 'checks.aarch64-darwin.ghciwatch-fmt'...
-derivation evaluated to /nix/store/wjhs0l1njl5pyji53xlmfjrlya0wmz8p-ghciwatch-fmt-0.3.0.drv
-checking derivation 'checks.aarch64-darwin.ghciwatch-audit'...
-derivation evaluated to /nix/store/z0mps8dyj2ds7c0fn0819y5h5611033z-ghciwatch-audit-0.3.0.drv
-checking flake output 'packages'...
-checking derivation 'packages.aarch64-darwin.default'...
-derivation evaluated to /nix/store/41abbdyglw5x9vcsvd89xan3ydjf8d7r-ghciwatch-0.3.0.drv
-checking flake output 'apps'...
-checking flake output 'devShells'...
-checking derivation 'devShells.aarch64-darwin.default'...
-derivation evaluated to /nix/store/bc935gz7dylzmcpdb5cczr8gngv8pmdb-nix-shell.drv
-running 5 flake checks...
-warning: The check omitted these incompatible systems: aarch64-linux, x86_64-darwin, x86_64-linux
-Use '--all-systems' to check all.
-```

doc/manual/rl-next/print-value-in-coercion-error.md

@@ -1,24 +0,0 @@
----
-synopsis: Coercion errors include the failing value
-issues: #561
-prs: #9754
----
-
-The `error: cannot coerce a <TYPE> to a string` message now includes the value
-which caused the error.
-
-Before:
-
-```
-       error: cannot coerce a set to a string
-```
-
-After:
-
-```
-       error: cannot coerce a set to a string: { aesSupport = «thunk»;
-       avx2Support = «thunk»; avx512Support = «thunk»; avxSupport = «thunk»;
-       canExecute = «thunk»; config = «thunk»; darwinArch = «thunk»; darwinMinVersion
-       = «thunk»; darwinMinVersionVariable = «thunk»; darwinPlatform = «thunk»; «84
-       attributes elided»}
-```

doc/manual/rl-next/print-value-in-type-error.md

@@ -1,23 +0,0 @@
----
-synopsis: Type errors include the failing value
-issues: #561
-prs: #9753
----
-
-In errors like `value is an integer while a list was expected`, the message now
-includes the failing value.
-
-Before:
-
-```
-       error: value is a set while a string was expected
-```
-
-After:
-
-```
-       error: expected a string but found a set: { ghc810 = «thunk»;
-       ghc8102Binary = «thunk»; ghc8107 = «thunk»; ghc8107Binary = «thunk»;
-       ghc865Binary = «thunk»; ghc90 = «thunk»; ghc902 = «thunk»; ghc92 = «thunk»;
-       ghc924Binary = «thunk»; ghc925 = «thunk»;  «17 attributes elided»}
-```

doc/manual/rl-next/reduce-debugger-clutter.md

@@ -1,37 +0,0 @@
----
-synopsis: "Visual clutter in `--debugger` is reduced"
-prs: 9919
----
-
-Before:
-```
-info: breakpoint reached
-
-
-Starting REPL to allow you to inspect the current state of the evaluator.
-
-Welcome to Nix 2.20.0pre20231222_dirty. Type :? for help.
-
-nix-repl> :continue
-error: uh oh
-
-
-Starting REPL to allow you to inspect the current state of the evaluator.
-
-Welcome to Nix 2.20.0pre20231222_dirty. Type :? for help.
-
-nix-repl>
-```
-
-After:
-
-```
-info: breakpoint reached
-
-Nix 2.20.0pre20231222_dirty debugger
-Type :? for help.
-nix-repl> :continue
-error: uh oh
-
-nix-repl>
-```

doc/manual/rl-next/source-location-in-while-evaluating-attribute.md

@@ -1,23 +0,0 @@
----
-synopsis: "In the debugger, `while evaluating the attribute` errors now include position information"
-prs: 9915
----
-
-Before:
-
-```
-0: while evaluating the attribute 'python311.pythonForBuild.pkgs'
-0x600001522598
-```
-
-After:
-
-```
-0: while evaluating the attribute 'python311.pythonForBuild.pkgs'
-/nix/store/hg65h51xnp74ikahns9hyf3py5mlbbqq-source/overrides/default.nix:132:27
-
-   131|
-   132|       bootstrappingBase = pkgs.${self.python.pythonAttr}.pythonForBuild.pkgs;
-      |                           ^
-   133|     in
-```

doc/manual/rl-next/source-positions-in-errors.md

@@ -1,42 +0,0 @@
----
-synopsis: Source locations are printed more consistently in errors
-issues: 561
-prs: 9555
----
-
-Source location information is now included in error messages more
-consistently. Given this code:
-
-```nix
-let
-  attr = {foo = "bar";};
-  key = {};
-in
-  attr.${key}
-```
-
-Previously, Nix would show this unhelpful message when attempting to evaluate
-it:
-
-```
-error:
-       … while evaluating an attribute name
-
-       error: value is a set while a string was expected
-```
-
-Now, the error message displays where the problematic value was found:
-
-```
-error:
-       … while evaluating an attribute name
-
-         at bad.nix:4:11:
-
-            3|   key = {};
-            4| in attr.${key}
-             |           ^
-            5|
-
-       error: expected a string but found a set: { }
-```

doc/manual/rl-next/stack-overflow-segfaults.md

@@ -1,32 +0,0 @@
----
-synopsis: Some stack overflow segfaults are fixed
-issues: 9616
-prs: 9617
----
-
-The number of nested function calls has been restricted, to detect and report
-infinite function call recursions. The default maximum call depth is 10,000 and
-can be set with [the `max-call-depth`
-option](@docroot@/command-ref/conf-file.md#conf-max-call-depth).
-
-This fixes segfaults or the following unhelpful error message in many cases:
-
-    error: stack overflow (possible infinite recursion)
-
-Before:
-
-```
-$ nix-instantiate --eval --expr '(x: x x) (x: x x)'
-Segmentation fault: 11
-```
-
-After:
-
-```
-$ nix-instantiate --eval --expr '(x: x x) (x: x x)'
-error: stack overflow
-
-       at «string»:1:14:
-            1| (x: x x) (x: x x)
-             |              ^
-```

doc/manual/rl-next/with-error-reporting.md

@@ -1,31 +0,0 @@
----
-synopsis: Better error reporting for `with` expressions
-prs: 9658
----
-
-`with` expressions using non-attrset values to resolve variables are now reported with proper positions.
-
-Previously an incorrect `with` expression would report no position at all, making it hard to determine where the error originated:
-
-```
-nix-repl> with 1; a
-error:
-       … <borked>
-
-         at «none»:0: (source not available)
-
-       error: value is an integer while a set was expected
-```
-
-Now position information is preserved and reported as with most other errors:
-
-```
-nix-repl> with 1; a
-error:
-       … while evaluating the first subexpression of a with expression
-         at «string»:1:1:
-            1| with 1; a
-             | ^
-
-       error: expected a set but found an integer: 1
-```

doc/manual/src/SUMMARY.md.in

@@ -109,7 +109,6 @@
   - [CLI guideline](contributing/cli-guideline.md)
   - [C++ style guide](contributing/cxx.md)
 - [Release Notes](release-notes/release-notes.md)
-{{#include ./SUMMARY-rl-next.md}}
   - [Release 2.18 (2023-09-20)](release-notes/rl-2.18.md)
   - [Release 2.17 (2023-07-24)](release-notes/rl-2.17.md)
   - [Release 2.16 (2023-05-31)](release-notes/rl-2.16.md)

doc/manual/src/command-ref/nix-instantiate.md

@@ -35,51 +35,13 @@ standard input.
 
   - `--parse`\
     Just parse the input files, and print their abstract syntax trees on
-    standard output as a Nix expression.
+    standard output in ATerm format.
 
   - `--eval`\
     Just parse and evaluate the input files, and print the resulting
     values on standard output. No instantiation of store derivations
     takes place.
 
-    > **Warning**
-    >
-    > This option produces output which can be parsed as a Nix expression which
-    > will produce a different result than the input expression when evaluated.
-    > For example, these two Nix expressions print the same result despite
-    > having different meaning:
-    >
-    > ```console
-    > $ nix-instantiate --eval --expr '{ a = {}; }'
-    > { a = <CODE>; }
-    > $ nix-instantiate --eval --expr '{ a = <CODE>; }'
-    > { a = <CODE>; }
-    > ```
-    >
-    > For human-readable output, `nix eval` (experimental) is more informative:
-    >
-    > ```console
-    > $ nix-instantiate --eval --expr 'a: a'
-    > <LAMBDA>
-    > $ nix eval --expr 'a: a'
-    > «lambda @ «string»:1:1»
-    > ```
-    >
-    > For machine-readable output, the `--xml` option produces unambiguous
-    > output:
-    >
-    > ```console
-    > $ nix-instantiate --eval --xml --expr '{ foo = <CODE>; }'
-    > <?xml version='1.0' encoding='utf-8'?>
-    > <expr>
-    >   <attrs>
-    >     <attr column="3" line="1" name="foo">
-    >       <unevaluated />
-    >     </attr>
-    >   </attrs>
-    > </expr>
-    > ```
-
   - `--find-file`\
     Look up the given files in Nix’s search path (as specified by the
     `NIX_PATH` environment variable). If found, print the corresponding
@@ -99,11 +61,11 @@ standard input.
 
   - `--json`\
     When used with `--eval`, print the resulting value as an JSON
-    representation of the abstract syntax tree rather than as a Nix expression.
+    representation of the abstract syntax tree rather than as an ATerm.
 
   - `--xml`\
     When used with `--eval`, print the resulting value as an XML
-    representation of the abstract syntax tree rather than as a Nix expression.
+    representation of the abstract syntax tree rather than as an ATerm.
     The schema is the same as that used by the [`toXML`
     built-in](../language/builtins.md).
 
@@ -171,24 +133,28 @@ $ nix-instantiate --eval --xml --expr '1 + 2'
 The difference between non-strict and strict evaluation:
 
 ```console
-$ nix-instantiate --eval --xml --expr '{ x = {}; }'
-<?xml version='1.0' encoding='utf-8'?>
-<expr>
-  <attrs>
-    <attr column="3" line="1" name="x">
-      <unevaluated />
-    </attr>
-  </attrs>
-</expr>
+$ nix-instantiate --eval --xml --expr 'rec { x = "foo"; y = x; }'
+...
+  <attr name="x">
+    <string value="foo" />
+  </attr>
+  <attr name="y">
+    <unevaluated />
+  </attr>
+...
+```
 
-$ nix-instantiate --eval --xml --strict --expr '{ x = {}; }'
-<?xml version='1.0' encoding='utf-8'?>
-<expr>
-  <attrs>
-    <attr column="3" line="1" name="x">
-      <attrs>
-      </attrs>
-    </attr>
-  </attrs>
-</expr>
+Note that `y` is left unevaluated (the XML representation doesn’t
+attempt to show non-normal forms).
+
+```console
+$ nix-instantiate --eval --xml --strict --expr 'rec { x = "foo"; y = x; }'
+...
+  <attr name="x">
+    <string value="foo" />
+  </attr>
+  <attr name="y">
+    <string value="foo" />
+  </attr>
+...
 ```

doc/manual/src/command-ref/nix-shell.md

@@ -235,14 +235,14 @@ package like Terraform:
 
 ```bash
 #! /usr/bin/env nix-shell
-#! nix-shell -i bash --packages 'terraform.withPlugins (plugins: [ plugins.openstack ])'
+#! nix-shell -i bash --packages "terraform.withPlugins (plugins: [ plugins.openstack ])"
 
 terraform apply
 ```
 
 > **Note**
 >
-> You must use single or double quotes (`'`, `"`) when passing a simple Nix expression
+> You must use double quotes (`"`) when passing a simple Nix expression
 > in a nix-shell shebang.
 
 Finally, using the merging of multiple nix-shell shebangs the following
@@ -251,7 +251,7 @@ branch):
 
 ```haskell
 #! /usr/bin/env nix-shell
-#! nix-shell -i runghc --packages 'haskellPackages.ghcWithPackages (ps: [ps.download-curl ps.tagsoup])'
+#! nix-shell -i runghc --packages "haskellPackages.ghcWithPackages (ps: [ps.download-curl ps.tagsoup])"
 #! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-20.03.tar.gz
 
 import Network.Curl.Download

doc/manual/src/command-ref/opt-common.md

@@ -203,7 +203,3 @@ Most Nix commands accept the following command-line options:
   Fix corrupted or missing store paths by redownloading or rebuilding them.
   Note that this is slow because it requires computing a cryptographic hash of the contents of every path in the closure of the build.
   Also note the warning under `nix-store --repair-path`.
-
-> **Note**
->
-> See [`man nix.conf`](@docroot@/command-ref/conf-file.md#command-line-flags) for overriding configuration settings with command line flags.

doc/manual/src/contributing/hacking.md

@@ -31,7 +31,7 @@ This shell also adds `./outputs/bin/nix` to your `$PATH` so you can run `nix` im
 To get a shell with one of the other [supported compilation environments](#compilation-environments):
 
 ```console
-$ nix develop .#native-clangStdenvPackages
+$ nix develop .#native-clang11StdenvPackages
 ```
 
 > **Note**
@@ -42,8 +42,8 @@ $ nix develop .#native-clangStdenvPackages
 To build Nix itself in this shell:
 
 ```console
-[nix-shell]$ autoreconfPhase
-[nix-shell]$ configurePhase
+[nix-shell]$ ./bootstrap.sh
+[nix-shell]$ ./configure $configureFlags --prefix=$(pwd)/outputs/out
 [nix-shell]$ make -j $NIX_BUILD_CORES
 ```
 
@@ -75,7 +75,7 @@ $ nix-shell
 To get a shell with one of the other [supported compilation environments](#compilation-environments):
 
 ```console
-$ nix-shell --attr devShells.x86_64-linux.native-clangStdenvPackages
+$ nix-shell --attr devShells.x86_64-linux.native-clang11StdenvPackages
 ```
 
 > **Note**
@@ -86,7 +86,7 @@ $ nix-shell --attr devShells.x86_64-linux.native-clangStdenvPackages
 To build Nix itself in this shell:
 
 ```console
-[nix-shell]$ autoreconfPhase
+[nix-shell]$ ./bootstrap.sh
 [nix-shell]$ ./configure $configureFlags --prefix=$(pwd)/outputs/out
 [nix-shell]$ make -j $NIX_BUILD_CORES
 ```
@@ -146,31 +146,6 @@ $ nix build .#packages.aarch64-linux.default
 Cross-compiled builds are available for ARMv6 (`armv6l-linux`) and ARMv7 (`armv7l-linux`).
 Add more [system types](#system-type) to `crossSystems` in `flake.nix` to bootstrap Nix on unsupported platforms.
 
-### Building for multiple platforms at once
-
-It is useful to perform multiple cross and native builds on the same source tree,
-for example to ensure that better support for one platform doesn't break the build for another.
-In order to facilitate this, Nix has some support for being built out of tree – that is, placing build artefacts in a different directory than the source code:
-
-1. Create a directory for the build, e.g.
-
-   ```bash
-   mkdir build
-   ```
-
-2. Run the configure script from that directory, e.g.
-
-   ```bash
-   cd build
-   ../configure <configure flags>
-   ```
-
-3. Run make from the source directory, but with the build directory specified, e.g.
-
-   ```bash
-   make builddir=build <make flags>
-   ```
-
 ## System type
 
 Nix uses a string with he following format to identify the *system type* or *platform* it runs on:
@@ -310,40 +285,3 @@ can build it yourself:
 
 Metrics about the change in line/function coverage over time are also
 [available](https://hydra.nixos.org/job/nix/master/coverage#tabs-charts).
-
-## Add a release note
-
-`doc/manual/rl-next` contains release notes entries for all unreleased changes.
-
-User-visible changes should come with a release note.
-
-### Add an entry
-
-Here's what a complete entry looks like. The file name is not incorporated in the document.
-
-```
----
-synopsis: Basically a title
-issues: 1234
-prs: 1238
----
-
-Here's one or more paragraphs that describe the change.
-
-- It's markdown
-- Add references to the manual using @docroot@
-```
-
-Significant changes should add the following header, which moves them to the top.
-
-```
-significance: significant
-```
-
-<!-- Keep an eye on https://codeberg.org/fgaz/changelog-d/issues/1 -->
-See also the [format documentation](https://github.com/haskell/cabal/blob/master/CONTRIBUTING.md#changelog).
-
-### Build process
-
-Releases have a precomputed `rl-MAJOR.MINOR.md`, and no `rl-next.md`.
-Set `buildUnreleasedNotes = true;` in `flake.nix` to build the release notes on the fly.

doc/manual/src/contributing/testing.md

@@ -2,48 +2,10 @@
 
 ## Unit-tests
 
-The unit tests are defined using the [googletest] and [rapidcheck] frameworks.
-
-[googletest]: https://google.github.io/googletest/
-[rapidcheck]: https://github.com/emil-e/rapidcheck
-
-### Source and header layout
-
-> An example of some files, demonstrating much of what is described below
->
-> ```
-> src
-> ├── libexpr
-> │   ├── value/context.hh
-> │   ├── value/context.cc
-> │   │
-> │   …
->     └── tests
-> │       ├── value/context.hh
-> │       ├── value/context.cc
-> │       │
-> │       …
-> │
-> ├── unit-test-data
-> │   ├── libstore
-> │   │   ├── worker-protocol/content-address.bin
-> │   │   …
-> │   …
-> …
-> ```
-
-The unit tests for each Nix library (`libnixexpr`, `libnixstore`, etc..) live inside a directory `src/${library_shortname}/tests` within the directory for the library (`src/${library_shortname}`).
-
-The data is in `unit-test-data`, with one subdir per library, with the same name as where the code goes.
-For example, `libnixstore` code is in `src/libstore`, and its test data is in `unit-test-data/libstore`.
-The path to the `unit-test-data` directory is passed to the unit test executable with the environment variable `_NIX_TEST_UNIT_DATA`.
-
-> **Note**
-> Due to the way googletest works, downstream unit test executables will actually include and re-run upstream library tests.
-> Therefore it is important that the same value for `_NIX_TEST_UNIT_DATA` be used with the tests for each library.
-> That is why we have the test data nested within a single `unit-test-data` directory.
-
-### Running tests
+The unit-tests for each Nix library (`libexpr`, `libstore`, etc..) are defined
+under `tests/unit/{library_name}/tests` using the
+[googletest](https://google.github.io/googletest/) and
+[rapidcheck](https://github.com/emil-e/rapidcheck) frameworks.
 
 You can run the whole testsuite with `make check`, or the tests for a specific component with `make libfoo-tests_RUN`.
 Finer-grained filtering is also possible using the [--gtest_filter](https://google.github.io/googletest/advanced.html#running-a-subset-of-the-tests) command-line option, or the `GTEST_FILTER` environment variable.
@@ -60,24 +22,6 @@ It is important that these testing libraries don't contain any actual tests them
 On some platforms they would be run as part of every test executable that uses them, which is redundant.
 On other platforms they wouldn't be run at all.
 
-### Characterization testing
-
-See [below](#characterization-testing-1) for a broader discussion of characterization testing.
-
-Like with the functional characterization, `_NIX_TEST_ACCEPT=1` is also used.
-For example:
-```shell-session
-$ _NIX_TEST_ACCEPT=1 make libstore-tests-exe_RUN
-...
-[  SKIPPED ] WorkerProtoTest.string_read
-[  SKIPPED ] WorkerProtoTest.string_write
-[  SKIPPED ] WorkerProtoTest.storePath_read
-[  SKIPPED ] WorkerProtoTest.storePath_write
-...
-```
-will regenerate the "golden master" expected result for the `libnixstore` characterization tests.
-The characterization tests will mark themselves "skipped" since they regenerated the expected result instead of actually testing anything.
-
 ## Functional tests
 
 The functional tests reside under the `tests/functional` directory and are listed in `tests/functional/local.mk`.

doc/manual/src/installation/building-source.md

@@ -3,7 +3,7 @@
 After cloning Nix's Git repository, issue the following commands:
 
 ```console
-$ autoreconf -vfi
+$ ./bootstrap.sh
 $ ./configure options...
 $ make
 $ make install

doc/manual/src/language/advanced-attributes.md

@@ -261,9 +261,6 @@ Derivations can declare some infrequently used optional attributes.
     useful for very trivial derivations (such as `writeText` in Nixpkgs)
     that are cheaper to build than to substitute from a binary cache.
 
-    You may disable the effects of this attibute by enabling the
-    `always-allow-substitutes` configuration option in Nix.
-
     > **Note**
     >
     > You need to have a builder configured which satisfies the
@@ -274,21 +271,18 @@ Derivations can declare some infrequently used optional attributes.
 
   - [`__structuredAttrs`]{#adv-attr-structuredAttrs}\
     If the special attribute `__structuredAttrs` is set to `true`, the other derivation
-    attributes are serialised into a file in JSON format. The environment variable
-    `NIX_ATTRS_JSON_FILE` points to the exact location of that file both in a build
-    and a [`nix-shell`](../command-ref/nix-shell.md). This obviates the need for
-    [`passAsFile`](#adv-attr-passAsFile) since JSON files have no size restrictions,
-    unlike process environments.
+    attributes are serialised in JSON format and made available to the
+    builder via the file `.attrs.json` in the builder’s temporary
+    directory. This obviates the need for [`passAsFile`](#adv-attr-passAsFile) since JSON files
+    have no size restrictions, unlike process environments.
 
     It also makes it possible to tweak derivation settings in a structured way; see
     [`outputChecks`](#adv-attr-outputChecks) for example.
 
     As a convenience to Bash builders,
-    Nix writes a script that initialises shell variables
-    corresponding to all attributes that are representable in Bash. The
-    environment variable `NIX_ATTRS_SH_FILE` points to the exact
-    location of the script, both in a build and a
-    [`nix-shell`](../command-ref/nix-shell.md). This includes non-nested
+    Nix writes a script named `.attrs.sh` to the builder’s directory
+    that initialises shell variables corresponding to all attributes
+    that are representable in Bash. This includes non-nested
     (associative) arrays. For example, the attribute `hardening.format = true`
     ends up as the Bash associative array element `${hardening[format]}`.
 

doc/manual/src/language/derivations.md

@@ -123,11 +123,6 @@ The builder is executed as follows:
     
       - `NIX_STORE` is set to the path of the top-level Nix store
         directory (typically, `/nix/store`).
-
-      - `NIX_ATTRS_JSON_FILE` & `NIX_ATTRS_SH_FILE` if `__structuredAttrs`
-        is set to `true` for the dervation. A detailed explanation of this
-        behavior can be found in the
-        [section about structured attrs](./advanced-attributes.md#adv-attr-structuredAttrs).
     
       - For each output declared in `outputs`, the corresponding
         environment variable is set to point to the intended path in the

doc/manual/src/release-notes/rl-next.md

@@ -0,0 +1 @@
+# Release X.Y (202?-??-??)

flake.lock

@@ -16,18 +16,34 @@
         "type": "github"
       }
     },
+    "lowdown-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1633514407,
+        "narHash": "sha256-Dw32tiMjdK9t3ETl5fzGrutQTzh2rufgZV4A/BbxuD4=",
+        "owner": "kristapsdz",
+        "repo": "lowdown",
+        "rev": "d2c2b44ff6c27b936ec27358a2653caaef8f73b8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "kristapsdz",
+        "repo": "lowdown",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1709884566,
-        "narHash": "sha256-NSYJg2sfdO/XS3L8XN/59Zhzn0dqWm7XtVnKI2mHq3w=",
+        "lastModified": 1700748986,
+        "narHash": "sha256-/nqLrNU297h3PCw4QyDpZKZEUHmialJdZW2ceYFobds=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "2be119add7b37dc535da2dd4cba68e2cf8d1517e",
+        "rev": "9ba29e2346bc542e9909d1021e8fd7d4b3f64db0",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-23.11-small",
+        "ref": "nixos-23.05-small",
         "repo": "nixpkgs",
         "type": "github"
       }
@@ -51,6 +67,7 @@
     "root": {
       "inputs": {
         "flake-compat": "flake-compat",
+        "lowdown-src": "lowdown-src",
         "nixpkgs": "nixpkgs",
         "nixpkgs-regression": "nixpkgs-regression"
       }

flake.nix

@@ -1,21 +1,18 @@
 {
   description = "The purely functional package manager";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11-small";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05-small";
   inputs.nixpkgs-regression.url = "github:NixOS/nixpkgs/215d4d0fd80ca5163643b03a33fde804a29cc1e2";
+  inputs.lowdown-src = { url = "github:kristapsdz/lowdown"; flake = false; };
   inputs.flake-compat = { url = "github:edolstra/flake-compat"; flake = false; };
 
-  outputs = { self, nixpkgs, nixpkgs-regression, flake-compat }:
+  outputs = { self, nixpkgs, nixpkgs-regression, lowdown-src, flake-compat }:
 
     let
       inherit (nixpkgs) lib;
-      inherit (lib) fileset;
 
       officialRelease = true;
 
-      # Set to true to build the release notes for the next release.
-      buildUnreleasedNotes = false;
-
       version = lib.fileContents ./.version + versionSuffix;
       versionSuffix =
         if officialRelease
@@ -28,12 +25,9 @@
       darwinSystems = [ "x86_64-darwin" "aarch64-darwin" ];
       systems = linuxSystems ++ darwinSystems;
 
-      crossSystems = [
-        "armv6l-linux" "armv7l-linux"
-        "x86_64-freebsd13" "x86_64-netbsd"
-      ];
+      crossSystems = [ "armv6l-linux" "armv7l-linux" ];
 
-      stdenvs = [ "gccStdenv" "clangStdenv" "stdenv" "libcxxStdenv" "ccacheStdenv" ];
+      stdenvs = [ "gccStdenv" "clangStdenv" "clang11Stdenv" "stdenv" "libcxxStdenv" "ccacheStdenv" ];
 
       forAllSystems = lib.genAttrs systems;
 
@@ -48,23 +42,54 @@
             })
             stdenvs);
 
+      # Experimental fileset library: https://github.com/NixOS/nixpkgs/pull/222981
+      # Not an "idiomatic" flake input because:
+      #  - Propagation to dependent locks: https://github.com/NixOS/nix/issues/7730
+      #  - Subflake would download redundant and huge parent flake
+      #  - No git tree hash support: https://github.com/NixOS/nix/issues/6044
+      inherit (import (builtins.fetchTarball { url = "https://github.com/NixOS/nix/archive/1bdcd7fc8a6a40b2e805bad759b36e64e911036b.tar.gz"; sha256 = "sha256:14ljlpdsp4x7h1fkhbmc4bd3vsqnx8zdql4h3037wh09ad6a0893"; }))
+        fileset;
+
+      baseFiles =
+        # .gitignore has already been processed, so any changes in it are irrelevant
+        # at this point. It is not represented verbatim for test purposes because
+        # that would interfere with repo semantics.
+        fileset.fileFilter (f: f.name != ".gitignore") ./.;
+
+      nixSrc = fileset.toSource {
+        root = ./.;
+        fileset = fileset.intersect baseFiles (fileset.unions [
+          ./.version
+          ./boehmgc-coroutine-sp-fallback.diff
+          ./bootstrap.sh
+          ./configure.ac
+          ./doc
+          ./local.mk
+          ./m4
+          ./Makefile
+          ./Makefile.config.in
+          ./misc
+          ./mk
+          ./precompiled-headers.h
+          ./src
+          ./tests/functional
+          ./tests/unit
+          ./COPYING
+          ./scripts/local.mk
+          (fileset.fileFilter (f: lib.strings.hasPrefix "nix-profile" f.name) ./scripts)
+          # TODO: do we really need README.md? It doesn't seem used in the build.
+          ./README.md
+        ]);
+      };
+
       # Memoize nixpkgs for different platforms for efficiency.
       nixpkgsFor = forAllSystems
         (system: let
           make-pkgs = crossSystem: stdenv: import nixpkgs {
-            localSystem = {
-              inherit system;
-            };
-            crossSystem = if crossSystem == null then null else {
-              system = crossSystem;
-            } // lib.optionalAttrs (crossSystem == "x86_64-freebsd13") {
-              useLLVM = true;
-            };
+            inherit system crossSystem;
             overlays = [
               (overlayFor (p: p.${stdenv}))
             ];
-
-            config.permittedInsecurePackages = [ "nix-2.13.6" ];
           };
           stdenvs = forAllStdenvs (make-pkgs null);
           native = stdenvs.stdenvPackages;
@@ -74,6 +99,112 @@
           cross = forAllCrossSystems (crossSystem: make-pkgs crossSystem "stdenv");
         });
 
+      commonDeps =
+        { pkgs
+        , isStatic ? pkgs.stdenv.hostPlatform.isStatic
+        }:
+        with pkgs; rec {
+        # Use "busybox-sandbox-shell" if present,
+        # if not (legacy) fallback and hope it's sufficient.
+        sh = pkgs.busybox-sandbox-shell or (busybox.override {
+          useMusl = true;
+          enableStatic = true;
+          enableMinimal = true;
+          extraConfig = ''
+            CONFIG_FEATURE_FANCY_ECHO y
+            CONFIG_FEATURE_SH_MATH y
+            CONFIG_FEATURE_SH_MATH_64 y
+
+            CONFIG_ASH y
+            CONFIG_ASH_OPTIMIZE_FOR_SIZE y
+
+            CONFIG_ASH_ALIAS y
+            CONFIG_ASH_BASH_COMPAT y
+            CONFIG_ASH_CMDCMD y
+            CONFIG_ASH_ECHO y
+            CONFIG_ASH_GETOPTS y
+            CONFIG_ASH_INTERNAL_GLOB y
+            CONFIG_ASH_JOB_CONTROL y
+            CONFIG_ASH_PRINTF y
+            CONFIG_ASH_TEST y
+          '';
+        });
+
+        configureFlags =
+          lib.optionals stdenv.isLinux [
+            "--with-boost=${boost}/lib"
+            "--with-sandbox-shell=${sh}/bin/busybox"
+          ]
+          ++ lib.optionals (stdenv.isLinux && !(isStatic && stdenv.system == "aarch64-linux")) [
+            "LDFLAGS=-fuse-ld=gold"
+          ];
+
+        testConfigureFlags = [
+          "RAPIDCHECK_HEADERS=${lib.getDev rapidcheck}/extras/gtest/include"
+        ];
+
+        internalApiDocsConfigureFlags = [
+          "--enable-internal-api-docs"
+        ];
+
+        nativeBuildDeps =
+          [
+            buildPackages.bison
+            buildPackages.flex
+            (lib.getBin buildPackages.lowdown-nix)
+            buildPackages.mdbook
+            buildPackages.mdbook-linkcheck
+            buildPackages.autoconf-archive
+            buildPackages.autoreconfHook
+            buildPackages.pkg-config
+
+            # Tests
+            buildPackages.git
+            buildPackages.mercurial # FIXME: remove? only needed for tests
+            buildPackages.jq # Also for custom mdBook preprocessor.
+          ]
+          ++ lib.optionals stdenv.hostPlatform.isLinux [(buildPackages.util-linuxMinimal or buildPackages.utillinuxMinimal)];
+
+        buildDeps =
+          [ curl
+            bzip2 xz brotli editline
+            openssl sqlite
+            libarchive
+            boost
+            lowdown-nix
+          ]
+          ++ lib.optionals stdenv.isLinux [libseccomp]
+          ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
+          ++ lib.optional stdenv.hostPlatform.isx86_64 libcpuid;
+
+        checkDeps = [
+          gtest
+          rapidcheck
+        ];
+
+        internalApiDocsDeps = [
+          buildPackages.doxygen
+        ];
+
+        awsDeps = lib.optional (stdenv.isLinux || stdenv.isDarwin)
+          (aws-sdk-cpp.override {
+            apis = ["s3" "transfer"];
+            customMemoryManagement = false;
+          });
+
+        propagatedDeps =
+          [ ((boehmgc.override {
+              enableLargeConfig = true;
+            }).overrideAttrs(o: {
+              patches = (o.patches or []) ++ [
+                ./boehmgc-coroutine-sp-fallback.diff
+              ];
+            })
+            )
+            nlohmann_json
+          ];
+      };
+
       installScriptFor = systems:
         with nixpkgsFor.x86_64-linux.native;
         runCommand "installer-script"
@@ -108,40 +239,37 @@
             echo "file installer $out/install" >> $out/nix-support/hydra-build-products
           '';
 
-      testNixVersions = pkgs: client: daemon: let
-        nix = pkgs.callPackage ./package.nix {
-          pname =
-            "nix-tests"
-            + lib.optionalString
-            (lib.versionAtLeast daemon.version "2.4pre20211005" &&
-            lib.versionAtLeast client.version "2.4pre20211005")
-            "-${client.version}-against-${daemon.version}";
-
-            inherit fileset;
-        };
-      in nix.overrideAttrs (prevAttrs: {
+      testNixVersions = pkgs: client: daemon: with commonDeps { inherit pkgs; }; with pkgs.lib; pkgs.stdenv.mkDerivation {
         NIX_DAEMON_PACKAGE = daemon;
         NIX_CLIENT_PACKAGE = client;
+        name =
+          "nix-tests"
+          + optionalString
+            (versionAtLeast daemon.version "2.4pre20211005" &&
+             versionAtLeast client.version "2.4pre20211005")
+            "-${client.version}-against-${daemon.version}";
+        inherit version;
 
+        src = nixSrc;
+
+        VERSION_SUFFIX = versionSuffix;
+
+        nativeBuildInputs = nativeBuildDeps;
+        buildInputs = buildDeps ++ awsDeps ++ checkDeps;
+        propagatedBuildInputs = propagatedDeps;
+
+        enableParallelBuilding = true;
+
+        configureFlags = testConfigureFlags; # otherwise configure fails
         dontBuild = true;
         doInstallCheck = true;
 
-        configureFlags = prevAttrs.configureFlags ++ [
-          # We don't need the actual build here.
-          "--disable-build"
-        ];
-
         installPhase = ''
           mkdir -p $out
         '';
 
-        installCheckPhase = lib.optionalString pkgs.stdenv.hostPlatform.isDarwin ''
-          export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
-        '' + ''
-          mkdir -p src/nix-channel
-          make installcheck -j$NIX_BUILD_CORES -l$NIX_BUILD_CORES
-        '';
-      });
+        installCheckPhase = "make installcheck -j$NIX_BUILD_CORES -l$NIX_BUILD_CORES";
+      };
 
       binaryTarball = nix: pkgs:
         let
@@ -218,62 +346,166 @@
           '';
 
       overlayFor = getStdenv: final: prev:
-        let
-          currentStdenv = getStdenv final;
-          comDeps = with final; commonDeps {
-            inherit pkgs;
-            inherit (currentStdenv.hostPlatform) isStatic;
-          };
-        in {
+        let currentStdenv = getStdenv final; in
+        {
           nixStable = prev.nix;
 
           # Forward from the previous stage as we don’t want it to pick the lowdown override
           nixUnstable = prev.nixUnstable;
 
-          changelog-d = final.buildPackages.callPackage ./misc/changelog-d.nix { };
-          boehmgc-nix = (final.boehmgc.override {
-            enableLargeConfig = true;
-          }).overrideAttrs (o: {
-            patches = (o.patches or [ ]) ++ [
-              ./boehmgc-coroutine-sp-fallback.diff
+          nix =
+          with final;
+          with commonDeps {
+            inherit pkgs;
+            inherit (currentStdenv.hostPlatform) isStatic;
+          };
+          let
+            canRunInstalled = currentStdenv.buildPlatform.canExecute currentStdenv.hostPlatform;
+          in currentStdenv.mkDerivation (finalAttrs: {
+            name = "nix-${version}";
+            inherit version;
 
-              # https://github.com/ivmai/bdwgc/pull/586
-              ./boehmgc-traceable_allocator-public.diff
-            ];
+            src = nixSrc;
+            VERSION_SUFFIX = versionSuffix;
+
+            outputs = [ "out" "dev" "doc" ];
+
+            nativeBuildInputs = nativeBuildDeps;
+            buildInputs = buildDeps
+              # There have been issues building these dependencies
+              ++ lib.optionals (currentStdenv.hostPlatform == currentStdenv.buildPlatform) awsDeps
+              ++ lib.optionals finalAttrs.doCheck checkDeps;
+
+            propagatedBuildInputs = propagatedDeps;
+
+            disallowedReferences = [ boost ];
+
+            preConfigure = lib.optionalString (! currentStdenv.hostPlatform.isStatic)
+              ''
+                # Copy libboost_context so we don't get all of Boost in our closure.
+                # https://github.com/NixOS/nixpkgs/issues/45462
+                mkdir -p $out/lib
+                cp -pd ${boost}/lib/{libboost_context*,libboost_thread*,libboost_system*} $out/lib
+                rm -f $out/lib/*.a
+                ${lib.optionalString currentStdenv.hostPlatform.isLinux ''
+                  chmod u+w $out/lib/*.so.*
+                  patchelf --set-rpath $out/lib:${currentStdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
+                ''}
+                ${lib.optionalString currentStdenv.hostPlatform.isDarwin ''
+                  for LIB in $out/lib/*.dylib; do
+                    chmod u+w $LIB
+                    install_name_tool -id $LIB $LIB
+                    install_name_tool -delete_rpath ${boost}/lib/ $LIB || true
+                  done
+                  install_name_tool -change ${boost}/lib/libboost_system.dylib $out/lib/libboost_system.dylib $out/lib/libboost_thread.dylib
+                ''}
+              '';
+
+            configureFlags = configureFlags ++
+              [ "--sysconfdir=/etc" ] ++
+              lib.optional stdenv.hostPlatform.isStatic "--enable-embedded-sandbox-shell" ++
+              [ (lib.enableFeature finalAttrs.doCheck "tests") ] ++
+              lib.optionals finalAttrs.doCheck testConfigureFlags ++
+              lib.optional (!canRunInstalled) "--disable-doc-gen";
+
+            enableParallelBuilding = true;
+
+            makeFlags = "profiledir=$(out)/etc/profile.d PRECOMPILE_HEADERS=1";
+
+            doCheck = true;
+
+            installFlags = "sysconfdir=$(out)/etc";
+
+            postInstall = ''
+              mkdir -p $doc/nix-support
+              echo "doc manual $doc/share/doc/nix/manual" >> $doc/nix-support/hydra-build-products
+              ${lib.optionalString currentStdenv.hostPlatform.isStatic ''
+              mkdir -p $out/nix-support
+              echo "file binary-dist $out/bin/nix" >> $out/nix-support/hydra-build-products
+              ''}
+              ${lib.optionalString currentStdenv.isDarwin ''
+              install_name_tool \
+                -change ${boost}/lib/libboost_context.dylib \
+                $out/lib/libboost_context.dylib \
+                $out/lib/libnixutil.dylib
+              ''}
+            '';
+
+            doInstallCheck = finalAttrs.doCheck;
+            installCheckFlags = "sysconfdir=$(out)/etc";
+            installCheckTarget = "installcheck"; # work around buggy detection in stdenv
+
+            separateDebugInfo = !currentStdenv.hostPlatform.isStatic;
+
+            strictDeps = true;
+
+            hardeningDisable = lib.optional stdenv.hostPlatform.isStatic "pie";
+
+            passthru.perl-bindings = with final; perl.pkgs.toPerlModule (currentStdenv.mkDerivation {
+              name = "nix-perl-${version}";
+
+              src = self;
+
+              nativeBuildInputs =
+                [ buildPackages.autoconf-archive
+                  buildPackages.autoreconfHook
+                  buildPackages.pkg-config
+                ];
+
+              buildInputs =
+                [ nix
+                  curl
+                  bzip2
+                  xz
+                  pkgs.perl
+                  boost
+                ]
+                ++ lib.optional (currentStdenv.isLinux || currentStdenv.isDarwin) libsodium
+                ++ lib.optional currentStdenv.isDarwin darwin.apple_sdk.frameworks.Security;
+
+              configureFlags = [
+                "--with-dbi=${perlPackages.DBI}/${pkgs.perl.libPrefix}"
+                "--with-dbd-sqlite=${perlPackages.DBDSQLite}/${pkgs.perl.libPrefix}"
+              ];
+
+              enableParallelBuilding = true;
+
+              postUnpack = "sourceRoot=$sourceRoot/perl";
+            });
+
+            meta.platforms = lib.platforms.unix;
           });
 
-          default-busybox-sandbox-shell = final.busybox.override {
-            useMusl = true;
-            enableStatic = true;
-            enableMinimal = true;
-            extraConfig = ''
-              CONFIG_FEATURE_FANCY_ECHO y
-              CONFIG_FEATURE_SH_MATH y
-              CONFIG_FEATURE_SH_MATH_64 y
+          lowdown-nix = with final; currentStdenv.mkDerivation rec {
+            name = "lowdown-0.9.0";
 
-              CONFIG_ASH y
-              CONFIG_ASH_OPTIMIZE_FOR_SIZE y
+            src = lowdown-src;
 
-              CONFIG_ASH_ALIAS y
-              CONFIG_ASH_BASH_COMPAT y
-              CONFIG_ASH_CMDCMD y
-              CONFIG_ASH_ECHO y
-              CONFIG_ASH_GETOPTS y
-              CONFIG_ASH_INTERNAL_GLOB y
-              CONFIG_ASH_JOB_CONTROL y
-              CONFIG_ASH_PRINTF y
-              CONFIG_ASH_TEST y
+            outputs = [ "out" "bin" "dev" ];
+
+            nativeBuildInputs = [ buildPackages.which ];
+
+            configurePhase = ''
+                ${if (currentStdenv.isDarwin && currentStdenv.isAarch64) then "echo \"HAVE_SANDBOX_INIT=false\" > configure.local" else ""}
+                ./configure \
+                  PREFIX=${placeholder "dev"} \
+                  BINDIR=${placeholder "bin"}/bin
             '';
           };
-
-          nix = final.callPackage ./package.nix {
-            inherit versionSuffix fileset;
-            stdenv = currentStdenv;
-            boehmgc = final.boehmgc-nix;
-            busybox-sandbox-shell = final.busybox-sandbox-shell or final.default-busybox-sandbox-shell;
-          };
         };
 
+      nixos-lib = import (nixpkgs + "/nixos/lib") { };
+
+      # https://nixos.org/manual/nixos/unstable/index.html#sec-calling-nixos-tests
+      runNixOSTestFor = system: test: nixos-lib.runTest {
+        imports = [ test ];
+        hostPkgs = nixpkgsFor.${system}.native;
+        defaults = {
+          nixpkgs.pkgs = nixpkgsFor.${system}.native;
+        };
+        _module.args.nixpkgs = nixpkgs;
+      };
+
     in {
       # A Nixpkgs overlay that overrides the 'nix' and
       # 'nix.perl-bindings' packages.
@@ -284,6 +516,21 @@
         # Binary package for various platforms.
         build = forAllSystems (system: self.packages.${system}.nix);
 
+        buildStatic = lib.genAttrs linux64BitSystems (system: self.packages.${system}.nix-static);
+
+        buildCross = forAllCrossSystems (crossSystem:
+          lib.genAttrs ["x86_64-linux"] (system: self.packages.${system}."nix-${crossSystem}"));
+
+        buildNoGc = forAllSystems (system: self.packages.${system}.nix.overrideAttrs (a: { configureFlags = (a.configureFlags or []) ++ ["--enable-gc=no"];}));
+
+        buildNoTests = forAllSystems (system:
+          self.packages.${system}.nix.overrideAttrs (a: {
+            doCheck =
+              assert ! a?dontCheck;
+              false;
+          })
+        );
+
         # Perl bindings for various platforms.
         perlBindings = forAllSystems (system: nixpkgsFor.${system}.native.nix.perl-bindings);
 
@@ -292,53 +539,126 @@
         # the installation script.
         binaryTarball = forAllSystems (system: binaryTarball nixpkgsFor.${system}.native.nix nixpkgsFor.${system}.native);
 
+        binaryTarballCross = lib.genAttrs ["x86_64-linux"] (system:
+          forAllCrossSystems (crossSystem:
+            binaryTarball
+              self.packages.${system}."nix-${crossSystem}"
+              nixpkgsFor.${system}.cross.${crossSystem}));
+
+        # The first half of the installation script. This is uploaded
+        # to https://nixos.org/nix/install. It downloads the binary
+        # tarball for the user's system and calls the second half of the
+        # installation script.
+        installerScript = installScriptFor [ "x86_64-linux" "i686-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" "armv6l-linux" "armv7l-linux" ];
+        installerScriptForGHA = installScriptFor [ "x86_64-linux" "x86_64-darwin" "armv6l-linux" "armv7l-linux"];
+
         # docker image with Nix inside
         dockerImage = lib.genAttrs linux64BitSystems (system: self.packages.${system}.dockerImage);
 
-        # API docs for Nix's unstable internal C++ interfaces.
-        internal-api-docs = let
-          nixpkgs = nixpkgsFor.x86_64-linux.native;
-          inherit (nixpkgs) pkgs;
+        # Line coverage analysis.
+        coverage =
+          with nixpkgsFor.x86_64-linux.native;
+          with commonDeps { inherit pkgs; };
 
-          nix = pkgs.callPackage ./package.nix {
-            inherit versionSuffix fileset officialRelease buildUnreleasedNotes;
-            inherit (pkgs) changelog-d;
-            internalApiDocs = true;
-            boehmgc = pkgs.boehmgc-nix;
-            busybox-sandbox-shell = pkgs.busybox-sandbox-shell;
+          releaseTools.coverageAnalysis {
+            name = "nix-coverage-${version}";
+
+            src = nixSrc;
+
+            configureFlags = testConfigureFlags;
+
+            enableParallelBuilding = true;
+
+            nativeBuildInputs = nativeBuildDeps;
+            buildInputs = buildDeps ++ propagatedDeps ++ awsDeps ++ checkDeps;
+
+            dontInstall = false;
+
+            doInstallCheck = true;
+            installCheckTarget = "installcheck"; # work around buggy detection in stdenv
+
+            lcovFilter = [ "*/boost/*" "*-tab.*" ];
+
+            hardeningDisable = ["fortify"];
+
+            NIX_CFLAGS_COMPILE = "-DCOVERAGE=1";
           };
-        in
-          nix.overrideAttrs (prev: {
-            # This Hydra job is just for the internal API docs.
-            # We don't need the build artifacts here.
+
+        # API docs for Nix's unstable internal C++ interfaces.
+        internal-api-docs =
+          with nixpkgsFor.x86_64-linux.native;
+          with commonDeps { inherit pkgs; };
+
+          stdenv.mkDerivation {
+            pname = "nix-internal-api-docs";
+            inherit version;
+
+            src = nixSrc;
+
+            configureFlags = testConfigureFlags ++ internalApiDocsConfigureFlags;
+
+            nativeBuildInputs = nativeBuildDeps;
+            buildInputs = buildDeps ++ propagatedDeps
+              ++ awsDeps ++ checkDeps ++ internalApiDocsDeps;
+
             dontBuild = true;
-            doCheck = false;
-            doInstallCheck = false;
-          });
+
+            installTargets = [ "internal-api-html" ];
+
+            postInstall = ''
+              mkdir -p $out/nix-support
+              echo "doc internal-api-docs $out/share/doc/nix/internal-api/html" >> $out/nix-support/hydra-build-products
+            '';
+          };
 
         # System tests.
-        tests = import ./tests/nixos { inherit lib nixpkgs nixpkgsFor; } // {
+        tests.authorization = runNixOSTestFor "x86_64-linux" ./tests/nixos/authorization.nix;
 
-          # Make sure that nix-env still produces the exact same result
-          # on a particular version of Nixpkgs.
-          evalNixpkgs =
-            with nixpkgsFor.x86_64-linux.native;
-            runCommand "eval-nixos" { buildInputs = [ nix ]; }
-              ''
-                type -p nix-env
-                # Note: we're filtering out nixos-install-tools because https://github.com/NixOS/nixpkgs/pull/153594#issuecomment-1020530593.
-                time nix-env --store dummy:// -f ${nixpkgs-regression} -qaP --drv-path | sort | grep -v nixos-install-tools > packages
-                [[ $(sha1sum < packages | cut -c1-40) = 402242fca90874112b34718b8199d844e8b03d12 ]]
-                mkdir $out
-              '';
+        tests.remoteBuilds = runNixOSTestFor "x86_64-linux" ./tests/nixos/remote-builds.nix;
 
-          nixpkgsLibTests =
-            forAllSystems (system:
-              import (nixpkgs + "/lib/tests/release.nix")
-                { pkgs = nixpkgsFor.${system}.native;
-                  nixVersions = [ self.packages.${system}.nix ];
-                }
-            );
+        tests.nix-copy-closure = runNixOSTestFor "x86_64-linux" ./tests/nixos/nix-copy-closure.nix;
+
+        tests.nix-copy = runNixOSTestFor "x86_64-linux" ./tests/nixos/nix-copy.nix;
+
+        tests.nssPreload = runNixOSTestFor "x86_64-linux" ./tests/nixos/nss-preload.nix;
+
+        tests.githubFlakes = runNixOSTestFor "x86_64-linux" ./tests/nixos/github-flakes.nix;
+
+        tests.sourcehutFlakes = runNixOSTestFor "x86_64-linux" ./tests/nixos/sourcehut-flakes.nix;
+
+        tests.tarballFlakes = runNixOSTestFor "x86_64-linux" ./tests/nixos/tarball-flakes.nix;
+
+        tests.containers = runNixOSTestFor "x86_64-linux" ./tests/nixos/containers/containers.nix;
+
+        tests.setuid = lib.genAttrs
+          ["i686-linux" "x86_64-linux"]
+          (system: runNixOSTestFor system ./tests/nixos/setuid.nix);
+
+
+        # Make sure that nix-env still produces the exact same result
+        # on a particular version of Nixpkgs.
+        tests.evalNixpkgs =
+          with nixpkgsFor.x86_64-linux.native;
+          runCommand "eval-nixos" { buildInputs = [ nix ]; }
+            ''
+              type -p nix-env
+              # Note: we're filtering out nixos-install-tools because https://github.com/NixOS/nixpkgs/pull/153594#issuecomment-1020530593.
+              time nix-env --store dummy:// -f ${nixpkgs-regression} -qaP --drv-path | sort | grep -v nixos-install-tools > packages
+              [[ $(sha1sum < packages | cut -c1-40) = ff451c521e61e4fe72bdbe2d0ca5d1809affa733 ]]
+              mkdir $out
+            '';
+
+        tests.nixpkgsLibTests =
+          forAllSystems (system:
+            import (nixpkgs + "/lib/tests/release.nix")
+              { pkgs = nixpkgsFor.${system}.native;
+                nixVersions = [ self.packages.${system}.nix ];
+              }
+          );
+
+        metrics.nixpkgs = import "${nixpkgs-regression}/pkgs/top-level/metrics.nix" {
+          pkgs = nixpkgsFor.x86_64-linux.native;
+          nixpkgs = nixpkgs-regression;
         };
 
         installTests = forAllSystems (system:
@@ -354,6 +674,12 @@
             # `NIX_DAEMON_SOCKET_PATH` which is required for the tests to work
             # againstLatestStable = testNixVersions pkgs pkgs.nix pkgs.nixStable;
           } "touch $out");
+
+        installerTests = import ./tests/installer {
+          binaryTarballs = self.hydraJobs.binaryTarball;
+          inherit nixpkgsFor;
+        };
+
       };
 
       checks = forAllSystems (system: {
@@ -361,11 +687,6 @@
         perlBindings = self.hydraJobs.perlBindings.${system};
         installTests = self.hydraJobs.installTests.${system};
         nixpkgsLibTests = self.hydraJobs.tests.nixpkgsLibTests.${system};
-        rl-next =
-          let pkgs = nixpkgsFor.${system}.native;
-          in pkgs.buildPackages.runCommand "test-rl-next-release-notes" { } ''
-          LANG=C.UTF-8 ${pkgs.changelog-d}/bin/changelog-d ${./doc/manual/rl-next} >$out
-        '';
       } // (lib.optionalAttrs (builtins.elem system linux64BitSystems)) {
         dockerImage = self.hydraJobs.dockerImage.${system};
       });
@@ -404,26 +725,27 @@
 
       devShells = let
         makeShell = pkgs: stdenv:
-          let
-            nix = pkgs.callPackage ./package.nix {
-              inherit stdenv versionSuffix fileset;
-              boehmgc = pkgs.boehmgc-nix;
-              busybox-sandbox-shell = pkgs.busybox-sandbox-shell or pkgs.default-busybox-sandbox;
-            };
-          in
-            nix.overrideAttrs (prev: {
-              nativeBuildInputs = prev.nativeBuildInputs
-                ++ lib.optional (stdenv.cc.isClang && !stdenv.buildPlatform.isDarwin) pkgs.buildPackages.bear
-                ++ lib.optional
-                  (stdenv.cc.isClang && stdenv.hostPlatform == stdenv.buildPlatform)
-                  pkgs.buildPackages.clang-tools;
+          with commonDeps { inherit pkgs; };
+          stdenv.mkDerivation {
+            name = "nix";
 
-              src = null;
+            outputs = [ "out" "dev" "doc" ];
 
-              installFlags = "sysconfdir=$(out)/etc";
-              strictDeps = false;
+            nativeBuildInputs = nativeBuildDeps
+                                ++ (lib.optionals stdenv.cc.isClang [ pkgs.bear pkgs.clang-tools ]);
 
-              shellHook = ''
+            buildInputs = buildDeps ++ propagatedDeps
+              ++ awsDeps ++ checkDeps ++ internalApiDocsDeps;
+
+            configureFlags = configureFlags
+              ++ testConfigureFlags ++ internalApiDocsConfigureFlags;
+
+            enableParallelBuilding = true;
+
+            installFlags = "sysconfdir=$(out)/etc";
+
+            shellHook =
+              ''
                 PATH=$prefix/bin:$PATH
                 unset PYTHONPATH
                 export MANPATH=$out/share/man:$MANPATH
@@ -431,7 +753,7 @@
                 # Make bash completion work.
                 XDG_DATA_DIRS+=:$out/share
               '';
-            });
+          };
         in
         forAllSystems (system:
           let

local.mk

@@ -1,3 +1,5 @@
+clean-files += Makefile.config
+
 GLOBAL_CXXFLAGS += -Wno-deprecated-declarations -Werror=switch
 # Allow switch-enum to be overridden for files that do not support it, usually because of dependency headers.
 ERROR_SWITCH_ENUM = -Werror=switch-enum

m4/gcc_bug_80431.m4

@@ -1,64 +0,0 @@
-# Ensure that this bug is not present in the C++ toolchain we are using.
-#
-# URL for bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80431
-#
-# The test program is from that issue, with only a slight modification
-# to set an exit status instead of printing strings.
-AC_DEFUN([ENSURE_NO_GCC_BUG_80431],
-[
-  AC_MSG_CHECKING([that GCC bug 80431 is fixed])
-  AC_LANG_PUSH(C++)
-  AC_RUN_IFELSE(
-    [AC_LANG_PROGRAM(
-      [[
-        #include <cstdio>
-
-        static bool a = true;
-        static bool b = true;
-
-        struct Options { };
-
-        struct Option
-        {
-            Option(Options * options)
-            {
-                a = false;
-            }
-
-            ~Option()
-            {
-                b = false;
-            }
-        };
-
-        struct MyOptions : Options { };
-
-        struct MyOptions2 : virtual MyOptions
-        {
-            Option foo{this};
-        };
-      ]],
-      [[
-        {
-            MyOptions2 opts;
-        }
-        return (a << 1) | b;
-      ]])],
-    [status_80431=0],
-    [status_80431=$?],
-    [
-      # Assume we're bug-free when cross-compiling
-    ])
-  AC_LANG_POP(C++)
-  AS_CASE([$status_80431],
-    [0],[
-      AC_MSG_RESULT(yes)
-    ],
-    [2],[
-      AC_MSG_RESULT(no)
-      AC_MSG_ERROR(Cannot build Nix with C++ compiler with this bug)
-    ],
-    [
-      AC_MSG_RESULT(unexpected result $status_80431: not expected failure with bug, ignoring)
-    ])
-])

maintainers/release-notes

@@ -1,179 +0,0 @@
-#!/usr/bin/env nix-shell
-#!nix-shell -i bash ../shell.nix -I nixpkgs=channel:nixos-unstable-small
-#                                   ^^^^^^^
-#                Only used for bash. shell.nix goes to the flake.
-
-# --- CONFIGURATION ---
-
-# This does double duty for
-# - including rl-next
-# - marking where to insert new links (right after)
-SUMMARY_MARKER_LINE='{{#include ./SUMMARY-rl-next.md}}'
-
-# --- LIB ---
-
-log() {
-  echo 1>&2 "release-notes:" "$@"
-}
-logcmd() {
-  local cmd="$1"
-  shift
-  logcmd2 "$cmd" "${*@Q}" "$cmd" "$@"
-}
-logcmd2() {
-  local fakecmd="$1"
-  local fakeargs="$2"
-  shift
-  shift
-  printf 1>&2 "release-notes: \033[34;1m$fakecmd\033[0m "
-  echo "$fakeargs" 1>&2
-  "$@"
-}
-die() {
-  # ANSI red
-  printf 1>&2 "release-notes: \033[31;1merror:\033[0m"
-  echo 1>&2 "" "$@"
-  exit 1
-}
-confirm() {
-  local answer
-  echo 1>&2 "$@" "[y/n]"
-  read -r answer
-  case "$answer" in
-    y|Y|yes|Yes|YES)
-      return 0
-      ;;
-    n|N|no|No|NO)
-      return 1
-      ;;
-    *)
-      echo 1>&2 "please answer y or n"
-      confirm "$@"
-      ;;
-  esac
-}
-report_done() {
-  logcmd2 "git" "show" git -c pager.show=false show
-  printf 1>&2 "release-notes: \033[32;1mdone\033[0m\n"
-}
-
-# --- PARSE ARGS ---
-
-if [[ $# -gt 0 ]]; then
-  die "Release notes takes no arguments, but make sure to set VERSION."
-fi
-
-# --- CHECKS ---
-
-if [[ ! -e flake.nix ]] || [[ ! -e .git ]]; then
-  die "must run in repo root"
-  exit 1
-fi
-
-# repo must be clean
-if ! git diff --quiet; then
-  die "repo is dirty, please commit or stash changes"
-fi
-
-if ! git diff --quiet --cached; then
-  die "repo has staged changes, please commit or stash them"
-fi
-
-if ! grep "$SUMMARY_MARKER_LINE" doc/manual/src/SUMMARY.md.in >/dev/null; then
-  # would have been nice to catch this early, but won't be worth the extra infra
-  die "SUMMARY.md.in is missing the marker line '$SUMMARY_MARKER_LINE', which would be used for inserting a new release notes page. Please fix the script."
-fi
-
-if [[ ! -n "${VERSION:-}" ]]; then
-  die "please set the VERSION environment variable before invoking this script"
-  exit 1
-fi
-
-# version_major_minor:      MAJOR.MINOR
-# version_full:             MAJOR.MINOR.PATCH
-# IS_PATCH:                 true if this is a patch release; append instead of create
-if grep -E '^[0-9]+\.[0-9]+$' <<< "$VERSION" >/dev/null; then
-  log 'is minor'
-  IS_PATCH=false
-  version_full="$VERSION.0"
-  version_major_minor="$VERSION"
-elif grep -E '^[0-9]+\.[0-9]+\.0$' <<< "$VERSION" >/dev/null; then
-  log 'is minor (.0)'
-  IS_PATCH=false
-  version_full="$VERSION"
-  version_major_minor="$(echo "$VERSION" | sed -e 's/\.0$//')"
-elif grep -E '^[0-9]+\.[0-9]+\.[0-9]+$' <<< "$VERSION" >/dev/null; then
-  log 'is patch'
-  IS_PATCH=true
-  version_full="$VERSION"
-  version_major_minor="$(echo "$VERSION" | sed -e 's/\.[0-9]*$//')"
-else
-  die "VERSION must be MAJOR.MINOR[.PATCH], where each is a number, e.g. 2.20 or 2.20.1 (VERSION was set to $VERSION)"
-fi
-
-unset VERSION
-
-log "version_major_minor=$version_major_minor"
-log "version_full=$version_full"
-log "IS_PATCH=$IS_PATCH"
-
-basename=rl-${version_major_minor}.md
-file=doc/manual/src/release-notes/$basename
-
-if ! $IS_PATCH; then
-  if [[ -e $file ]]; then
-    die "release notes file $file already exists. If you'd like to make a minor release, pass a patch version, e.g. 2.20.1"
-  fi
-fi
-
-# --- DEFAULTS ---
-
-if [[ ! -n "${DATE:-}" ]]; then
-  DATE="$(date +%Y-%m-%d)"
-  log "DATE not set, using $DATE"
-fi
-
-case "$DATE" in
-  [0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9])
-    ;;
-  *)
-    die "DATE must be YYYY-MM-DD, e.g. 2021-12-31 (DATE was set to $DATE)"
-    ;;
-esac
-
-# --- DO THE WORK ---
-
-# menu
-title="Release $version_major_minor ($DATE)"
-# section on page
-section_title="Release $version_full ($DATE)"
-
-(
-  # TODO add minor number, and append?
-  echo "# $section_title"
-  echo
-  changelog-d doc/manual/rl-next | sed -e 's/ *$//'
-) | tee -a $file
-
-log "Wrote $file"
-
-if ! $IS_PATCH; then
-  NEW_SUMMARY_LINE="  - [$title](release-notes/$basename)"
-
-  # find the marker line, insert new link after it
-  escaped_marker="$(echo "$SUMMARY_MARKER_LINE" | sed -e 's/\//\\\//g' -e 's/ /\\ /g')"
-  escaped_line="$(echo "$NEW_SUMMARY_LINE" | sed -e 's/\//\\\//g' -e 's/ /\\ /g')"
-  logcmd sed -i -e "/$escaped_marker/a $escaped_line" doc/manual/src/SUMMARY.md.in
-fi
-
-for f in doc/manual/rl-next/*.md; do
-  if [[ config != "$(basename $f)" ]]; then
-    logcmd git rm $f
-  fi
-done
-
-logcmd git add $file doc/manual/src/SUMMARY.md.in
-logcmd git status
-logcmd git commit -m "release notes: $version_full"
-
-report_done

maintainers/release-process.md

@@ -24,23 +24,34 @@ release:
 * In a checkout of the Nix repo, make sure you're on `master` and run
   `git pull`.
 
-* Compile the release notes by running
+* Move the contents of `doc/manual/src/release-notes/rl-next.md`
+  (except the first line) to
+  `doc/manual/src/release-notes/rl-$VERSION.md` (where `$VERSION` is
+  the contents of `.version` *without* the patch level, e.g. `2.12`
+  rather than `2.12.0`).
+
+* Add a header to `doc/manual/src/release-notes/rl-$VERSION.md` like
+
+  ```
+  # Release 2.12 (2022-12-06)
+  ```
+
+* Proof-read / edit / rearrange the release notes. Breaking changes
+  and highlights should go to the top.
+
+* Add a link to the release notes to `doc/manual/src/SUMMARY.md.in`
+  (*not* `SUMMARY.md`), e.g.
+
+  ```
+  - [Release 2.12 (2022-12-06)](release-notes/rl-2.12.md)
+  ```
+
+* Run
 
   ```console
   $ git checkout -b release-notes
-  $ VERSION=X.YY ./maintainers/release-notes
-  ```
-
-  where `X.YY` is *without* the patch level, e.g. `2.12` rather than ~~`2.12.0`~~.
-
-  A commit is created.
-
-* Proof-read / edit / rearrange the release notes if needed. Breaking changes
-  and highlights should go to the top.
-
-* Push.
-
-  ```console
+  $ git add doc/manual/src/release-notes/rl-$VERSION.md
+  $ git commit -a -m 'Release notes'
   $ git push --set-upstream $REMOTE release-notes
   ```
 
@@ -56,17 +67,15 @@ release:
   $ git checkout -b $VERSION-maintenance
   ```
 
-* Mark the release as official:
+* Mark the release as stable:
 
   ```console
-  $ sed -e 's/officialRelease = false;/officialRelease = true;/' -i flake.nix
+  $ git cherry-pick f673551e71942a52b6d7ae66af8b67140904a76a
   ```
 
   This removes the link to `rl-next.md` from the manual and sets
   `officialRelease = true` in `flake.nix`.
 
-* Commit
-
 * Push the release branch:
 
   ```console
@@ -150,30 +159,6 @@ release:
 
 ## Creating a point release
 
-* Checkout.
-
-  ```console
-  $ git checkout XX.YY-maintenance
-  ```
-
-* Determine the next patch version.
-
-  ```console
-  $ export VERSION=XX.YY.ZZ
-  ```
-
-* Update release notes.
-
-  ```console
-  $ ./maintainers/release-notes
-  ```
-
-* Push.
-
-  ```console
-  $ git push
-  ```
-
 * Wait for the desired evaluation of the maintenance jobset to finish
   building.
 

misc/changelog-d.cabal.nix

@@ -1,31 +0,0 @@
-{ mkDerivation, aeson, base, bytestring, cabal-install-parsers
-, Cabal-syntax, containers, directory, filepath, frontmatter
-, generic-lens-lite, lib, mtl, optparse-applicative, parsec, pretty
-, regex-applicative, text, pkgs
-}:
-let rev = "f30f6969e9cd8b56242309639d58acea21c99d06";
-in
-mkDerivation {
-  pname = "changelog-d";
-  version = "0.1";
-  src = pkgs.fetchurl {
-    name = "changelog-d-${rev}.tar.gz";
-    url = "https://codeberg.org/roberth/changelog-d/archive/${rev}.tar.gz";
-    hash = "sha256-8a2+i5u7YoszAgd5OIEW0eYUcP8yfhtoOIhLJkylYJ4=";
-  } // { inherit rev; };
-  isLibrary = false;
-  isExecutable = true;
-  libraryHaskellDepends = [
-    aeson base bytestring cabal-install-parsers Cabal-syntax containers
-    directory filepath frontmatter generic-lens-lite mtl parsec pretty
-    regex-applicative text
-  ];
-  executableHaskellDepends = [
-    base bytestring Cabal-syntax directory filepath
-    optparse-applicative
-  ];
-  doHaddock = false;
-  description = "Concatenate changelog entries into a single one";
-  license = lib.licenses.gpl3Plus;
-  mainProgram = "changelog-d";
-}

misc/changelog-d.nix

@@ -1,31 +0,0 @@
-# Taken temporarily from <nixpkgs/pkgs/by-name/ch/changelog-d/package.nix>
-{
-  callPackage,
-  lib,
-  haskell,
-  haskellPackages,
-}:
-
-let
-  hsPkg = haskellPackages.callPackage ./changelog-d.cabal.nix { };
-
-  addCompletions = haskellPackages.generateOptparseApplicativeCompletions ["changelog-d"];
-
-  haskellModifications =
-    lib.flip lib.pipe [
-      addCompletions
-      haskell.lib.justStaticExecutables
-    ];
-
-  mkDerivationOverrides = finalAttrs: oldAttrs: {
-
-    version = oldAttrs.version + "-git-${lib.strings.substring 0 7 oldAttrs.src.rev}";
-
-    meta = oldAttrs.meta // {
-      homepage = "https://codeberg.org/roberth/changelog-d";
-      maintainers = [ lib.maintainers.roberth ];
-    };
-
-  };
-in
-  (haskellModifications hsPkg).overrideAttrs mkDerivationOverrides

mk/build-dir.mk

@@ -1,10 +0,0 @@
-# Initialise support for build directories.
-builddir ?=
-
-ifdef builddir
-  buildprefix = $(builddir)/
-  buildprefixrel = $(builddir)
-else
-  buildprefix =
-  buildprefixrel = .
-endif

mk/install-dirs.mk

@@ -1,11 +0,0 @@
-# Default installation paths.
-prefix ?= /usr/local
-libdir ?= $(prefix)/lib
-bindir ?= $(prefix)/bin
-libexecdir ?= $(prefix)/libexec
-datadir ?= $(prefix)/share
-localstatedir ?= $(prefix)/var
-sysconfdir ?= $(prefix)/etc
-mandir ?= $(prefix)/share/man
-
-DESTDIR ?=

mk/lib.mk

@@ -43,6 +43,27 @@ define newline
 endef
 
 
+# Default installation paths.
+prefix ?= /usr/local
+libdir ?= $(prefix)/lib
+bindir ?= $(prefix)/bin
+libexecdir ?= $(prefix)/libexec
+datadir ?= $(prefix)/share
+localstatedir ?= $(prefix)/var
+sysconfdir ?= $(prefix)/etc
+mandir ?= $(prefix)/share/man
+
+
+# Initialise support for build directories.
+builddir ?=
+
+ifdef builddir
+  buildprefix = $(builddir)/
+else
+  buildprefix =
+endif
+
+
 # Pass -fPIC if we're building dynamic libraries.
 BUILD_SHARED_LIBS ?= 1
 
@@ -73,8 +94,6 @@ ifeq ($(BUILD_DEBUG), 1)
 endif
 
 
-include mk/build-dir.mk
-include mk/install-dirs.mk
 include mk/functions.mk
 include mk/tracing.mk
 include mk/clean.mk
@@ -93,7 +112,7 @@ define include-sub-makefile
   include $(1)
 endef
 
-$(foreach mf, $(makefiles), $(eval $(call include-sub-makefile,$(mf))))
+$(foreach mf, $(makefiles), $(eval $(call include-sub-makefile, $(mf))))
 
 
 # Instantiate stuff.
@@ -113,10 +132,6 @@ $(foreach test-group, $(install-tests-groups), \
     $(eval $(call run-install-test,$(test))) \
     $(eval $(test-group).test-group: $(test).test)))
 
-# Include makefiles requiring built programs.
-$(foreach mf, $(makefiles-late), $(eval $(call include-sub-makefile,$(mf))))
-
-
 $(foreach file, $(man-pages), $(eval $(call install-data-in, $(file), $(mandir)/man$(patsubst .%,%,$(suffix $(file))))))
 
 

mk/programs.mk

@@ -6,9 +6,6 @@ programs-list :=
 # - $(1)_NAME: the name of the program (e.g. ‘foo’); defaults to
 #   $(1).
 #
-# - $(1)_ENV: environment variables to set when running the program
-#   from the Makefile using the $(1)_RUN target.
-#
 # - $(1)_DIR: the directory where the (non-installed) program will be
 #   placed.
 #
@@ -90,6 +87,6 @@ define build-program
   # Phony target to run this program (typically as a dependency of 'check').
   .PHONY: $(1)_RUN
   $(1)_RUN: $$($(1)_PATH)
-	$(trace-test) $$($(1)_ENV) $$($(1)_PATH)
+	$(trace-test) $$($(1)_PATH)
 
 endef

mk/templates.mk

@@ -10,10 +10,10 @@ endef
 
 ifneq ($(MAKECMDGOALS), clean)
 
-$(buildprefix)%.h: %.h.in
-	$(trace-gen) rm -f $@ && cd $(buildprefixrel) && ./config.status --quiet --header=$(@:$(buildprefix)%=%)
+%.h: %.h.in
+	$(trace-gen) rm -f $@ && ./config.status --quiet --header=$@
 
-$(buildprefix)%: %.in
-	$(trace-gen) rm -f $@ && cd $(buildprefixrel) && ./config.status --quiet --file=$(@:$(buildprefix)%=%)
+%: %.in
+	$(trace-gen) rm -f $@ && ./config.status --quiet --file=$@
 
 endif

package.nix

@@ -1,260 +0,0 @@
-{
-  pkgs,
-  lib,
-  stdenv,
-  autoconf-archive,
-  autoreconfHook,
-  aws-sdk-cpp,
-  boehmgc,
-  nlohmann_json,
-  bison,
-  changelog-d,
-  boost,
-  brotli,
-  bzip2,
-  curl,
-  doxygen,
-  editline,
-  fileset,
-  flex,
-  git,
-  gtest,
-  jq,
-  libarchive,
-  libcpuid,
-  libseccomp,
-  libsodium,
-  lowdown,
-  mdbook,
-  mdbook-linkcheck,
-  mercurial,
-  openssl,
-  pkg-config,
-  rapidcheck,
-  sqlite,
-  util-linuxMinimal ? utillinuxMinimal,
-  utillinuxMinimal ? null,
-  xz,
-
-  busybox-sandbox-shell,
-
-  pname ? "nix",
-  versionSuffix ? "",
-  officialRelease ? true,
-  # Set to true to build the release notes for the next release.
-  buildUnreleasedNotes ? false,
-  internalApiDocs ? false,
-
-  # Not a real argument, just the only way to approximate let-binding some
-  # stuff for argument defaults.
-  __forDefaults ? {
-    canRunInstalled = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
-  },
-}: let
-  inherit (__forDefaults) canRunInstalled;
-
-  version = lib.fileContents ./.version + versionSuffix;
-
-  aws-sdk-cpp-nix = aws-sdk-cpp.override {
-    apis = [ "s3" "transfer" ];
-    customMemoryManagement = false;
-  };
-
-  testConfigureFlags = [
-    "RAPIDCHECK_HEADERS=${lib.getDev rapidcheck}/extras/gtest/include"
-  ];
-
-  # The internal API docs need these for the build, but if we're not building
-  # Nix itself, then these don't need to be propagated.
-  maybePropagatedInputs = [
-    boehmgc
-    nlohmann_json
-  ];
-
-  # .gitignore has already been processed, so any changes in it are irrelevant
-  # at this point. It is not represented verbatim for test purposes because
-  # that would interfere with repo semantics.
-  baseFiles = fileset.fileFilter (f: f.name != ".gitignore") ./.;
-
-  configureFiles = fileset.unions [
-    ./.version
-    ./configure.ac
-    ./m4
-    # TODO: do we really need README.md? It doesn't seem used in the build.
-    ./README.md
-  ];
-
-  topLevelBuildFiles = fileset.unions [
-    ./local.mk
-    ./Makefile
-    ./Makefile.config.in
-    ./mk
-  ];
-
- functionalTestFiles = fileset.unions [
-    ./tests/functional
-    ./tests/unit
-    (fileset.fileFilter (f: lib.strings.hasPrefix "nix-profile" f.name) ./scripts)
- ];
-
-in stdenv.mkDerivation (finalAttrs: {
-  inherit pname version;
-
-  src = fileset.toSource {
-    root = ./.;
-    fileset = fileset.intersection baseFiles (fileset.unions ([
-      configureFiles
-      topLevelBuildFiles
-      functionalTestFiles
-    ] ++ lib.optionals (!finalAttrs.dontBuild || internalApiDocs) [
-      ./boehmgc-coroutine-sp-fallback.diff
-      ./doc
-      ./misc
-      ./precompiled-headers.h
-      ./src
-      ./COPYING
-      ./scripts/local.mk
-    ]));
-  };
-
-  VERSION_SUFFIX = versionSuffix;
-
-  outputs = [ "out" ]
-    ++ lib.optionals (!finalAttrs.dontBuild) [ "dev" "doc" ];
-
-  dontBuild = false;
-
-  nativeBuildInputs = [
-    bison
-    flex
-  ] ++ [
-    (lib.getBin lowdown)
-    mdbook
-    mdbook-linkcheck
-    autoconf-archive
-    autoreconfHook
-    pkg-config
-
-    # Tests
-    git
-    mercurial
-    jq
-  ] ++ lib.optional stdenv.hostPlatform.isLinux util-linuxMinimal
-    ++ lib.optional (!officialRelease && buildUnreleasedNotes) changelog-d
-    ++ lib.optional internalApiDocs doxygen
-  ;
-
-  buildInputs = [
-    curl
-    bzip2
-    xz
-    brotli
-    editline
-    openssl
-    sqlite
-    libarchive
-    boost
-    lowdown
-    libsodium
-  ]
-    ++ lib.optionals stdenv.isLinux [ libseccomp ]
-    ++ lib.optional stdenv.hostPlatform.isx86_64 libcpuid
-    # There have been issues building these dependencies
-    ++ lib.optional (stdenv.hostPlatform == stdenv.buildPlatform) aws-sdk-cpp-nix
-    ++ lib.optionals (finalAttrs.dontBuild) maybePropagatedInputs
-  ;
-
-  checkInputs = [
-    gtest
-    rapidcheck
-  ];
-
-  propagatedBuildInputs = lib.optionals (!finalAttrs.dontBuild) maybePropagatedInputs;
-
-  disallowedReferences = [
-    boost
-  ];
-
-  preConfigure = lib.optionalString (!finalAttrs.dontBuild && !stdenv.hostPlatform.isStatic) ''
-    # Copy libboost_context so we don't get all of Boost in our closure.
-    # https://github.com/NixOS/nixpkgs/issues/45462
-    mkdir -p $out/lib
-    cp -pd ${boost}/lib/{libboost_context*,libboost_thread*,libboost_system*} $out/lib
-    rm -f $out/lib/*.a
-  '' + lib.optionalString (!finalAttrs.dontBuild && stdenv.hostPlatform.isLinux) ''
-    chmod u+w $out/lib/*.so.*
-    patchelf --set-rpath $out/lib:${stdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
-  '' + lib.optionalString (!finalAttrs.dontBuild && stdenv.hostPlatform.isDarwin) ''
-    for LIB in $out/lib/*.dylib; do
-      chmod u+w $LIB
-      install_name_tool -id $LIB $LIB
-      install_name_tool -delete_rpath ${boost}/lib/ $LIB || true
-    done
-    install_name_tool -change ${boost}/lib/libboost_system.dylib $out/lib/libboost_system.dylib $out/lib/libboost_thread.dylib
-  '' + ''
-    # Workaround https://github.com/NixOS/nixpkgs/issues/294890.
-    if [[ -n "''${doCheck:-}" ]]; then
-      appendToVar configureFlags "--enable-tests"
-    else
-      appendToVar configureFlags "--disable-tests"
-    fi
-  '';
-
-  configureFlags = lib.optionals stdenv.isLinux [
-    "--with-boost=${boost}/lib"
-    "--with-sandbox-shell=${busybox-sandbox-shell}/bin/busybox"
-  ] ++ lib.optionals (stdenv.isLinux && !(stdenv.hostPlatform.isStatic && stdenv.system == "aarch64-linux")) [
-    "LDFLAGS=-fuse-ld=gold"
-  ] ++ [ "--sysconfdir=/etc" ]
-    ++ lib.optional stdenv.hostPlatform.isStatic "--enable-embedded-sandbox-shell"
-    ++ lib.optionals (finalAttrs.doCheck || internalApiDocs) testConfigureFlags
-    ++ lib.optional (!canRunInstalled) "--disable-doc-gen"
-    ++ [ (lib.enableFeature internalApiDocs "internal-api-docs") ]
-  ;
-
-  installTargets = lib.optional internalApiDocs "internal-api-html";
-
-  enableParallelBuilding = true;
-
-  makeFlags = "profiledir=$(out)/etc/profile.d PRECOMPILE_HEADERS=1";
-
-  doCheck = true;
-
-  installFlags = "sysconfdir=$(out)/etc";
-
-  postInstall = lib.optionalString (!finalAttrs.dontBuild) ''
-    mkdir -p $doc/nix-support
-    echo "doc manual $doc/share/doc/nix/manual" >> $doc/nix-support/hydra-build-products
-  '' + lib.optionalString stdenv.hostPlatform.isStatic ''
-    mkdir -p $out/nix-support
-    echo "file binary-dist $out/bin/nix" >> $out/nix-support/hydra-build-products
-  '' + lib.optionalString stdenv.isDarwin ''
-    install_name_tool \
-      -change ${boost}/lib/libboost_context.dylib \
-      $out/lib/libboost_context.dylib \
-      $out/lib/libnixutil.dylib
-  '' + lib.optionalString internalApiDocs ''
-    mkdir -p $out/nix-support
-    echo "doc internal-api-docs $out/share/doc/nix/internal-api/html" >> "$out/nix-support/hydra-build-products"
-  '';
-
-  doInstallCheck = finalAttrs.doCheck;
-  installCheckFlags = "sysconfdir=$(out)/etc";
-  installCheckTarget = "installcheck"; # work around buggy detection in stdenv
-
-  preInstallCheck = lib.optionalString stdenv.hostPlatform.isDarwin ''
-    export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
-  '';
-
-  separateDebugInfo = !stdenv.hostPlatform.isStatic && !finalAttrs.dontBuild;
-
-  strictDeps = true;
-
-  hardeningDisable = lib.optional stdenv.hostPlatform.isStatic "pie";
-
-  meta.platforms = lib.platforms.unix;
-
-  passthru.perl-bindings = pkgs.callPackage ./perl {
-    inherit fileset stdenv;
-  };
-})

perl/Makefile

@@ -1,12 +1,6 @@
 makefiles = local.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -std=c++2a
-
-# A convenience for concurrent development of Nix and its Perl bindings.
-# Not needed in a standalone build of the Perl bindings.
-ifneq ("$(wildcard ../src)", "")
-  GLOBAL_CXXFLAGS += -I ../src
-endif
+GLOBAL_CXXFLAGS += -g -Wall -std=c++2a -I ../src
 
 -include Makefile.config
 

perl/default.nix

@@ -1,51 +0,0 @@
-{ lib, fileset
-, stdenv
-, perl, perlPackages
-, autoconf-archive, autoreconfHook, pkg-config
-, nix, curl, bzip2, xz, boost, libsodium, darwin
-}:
-
-perl.pkgs.toPerlModule (stdenv.mkDerivation {
-  name = "nix-perl-${nix.version}";
-
-  src = fileset.toSource {
-    root = ../.;
-    fileset = fileset.unions [
-      ../.version
-      ../m4
-      ../mk
-      ./MANIFEST
-      ./Makefile
-      ./Makefile.config.in
-      ./configure.ac
-      ./lib
-      ./local.mk
-    ];
-  };
-
-  nativeBuildInputs =
-    [ autoconf-archive
-      autoreconfHook
-      pkg-config
-    ];
-
-  buildInputs =
-    [ nix
-      curl
-      bzip2
-      xz
-      perl
-      boost
-    ]
-    ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
-    ++ lib.optional stdenv.isDarwin darwin.apple_sdk.frameworks.Security;
-
-  configureFlags = [
-    "--with-dbi=${perlPackages.DBI}/${perl.libPrefix}"
-    "--with-dbd-sqlite=${perlPackages.DBDSQLite}/${perl.libPrefix}"
-  ];
-
-  enableParallelBuilding = true;
-
-  postUnpack = "sourceRoot=$sourceRoot/perl";
-})

scripts/install-darwin-multi-user.sh

@@ -3,13 +3,11 @@
 set -eu
 set -o pipefail
 
-# System specific settings
-export NIX_FIRST_BUILD_UID="${NIX_FIRST_BUILD_UID:-301}"
-export NIX_BUILD_USER_NAME_TEMPLATE="_nixbld%d"
-
 readonly NIX_DAEMON_DEST=/Library/LaunchDaemons/org.nixos.nix-daemon.plist
 # create by default; set 0 to DIY, use a symlink, etc.
 readonly NIX_VOLUME_CREATE=${NIX_VOLUME_CREATE:-1} # now default
+NIX_FIRST_BUILD_UID="301"
+NIX_BUILD_USER_NAME_TEMPLATE="_nixbld%d"
 
 # caution: may update times on / if not run as normal non-root user
 read_only_root() {
@@ -102,7 +100,7 @@ poly_extra_try_me_commands() {
 poly_configure_nix_daemon_service() {
     task "Setting up the nix-daemon LaunchDaemon"
     _sudo "to set up the nix-daemon as a LaunchDaemon" \
-          /usr/bin/install -m "u=rw,go=r" "/nix/var/nix/profiles/default$NIX_DAEMON_DEST" "$NIX_DAEMON_DEST"
+          /usr/bin/install -m -rw-r--r-- "/nix/var/nix/profiles/default$NIX_DAEMON_DEST" "$NIX_DAEMON_DEST"
 
     _sudo "to load the LaunchDaemon plist for nix-daemon" \
           launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist

scripts/install-multi-user.sh

@@ -25,9 +25,9 @@ readonly RED='\033[31m'
 readonly NIX_USER_COUNT=${NIX_USER_COUNT:-32}
 readonly NIX_BUILD_GROUP_ID="${NIX_BUILD_GROUP_ID:-30000}"
 readonly NIX_BUILD_GROUP_NAME="nixbld"
-# each system specific installer must set these:
-#   NIX_FIRST_BUILD_UID
-#   NIX_BUILD_USER_NAME_TEMPLATE
+# darwin installer needs to override these
+NIX_FIRST_BUILD_UID="${NIX_FIRST_BUILD_UID:-30001}"
+NIX_BUILD_USER_NAME_TEMPLATE="nixbld%d"
 # Please don't change this. We don't support it, because the
 # default shell profile that comes with Nix doesn't support it.
 readonly NIX_ROOT="/nix"
@@ -699,12 +699,6 @@ EOF
     fi
 }
 
-check_required_system_specific_settings() {
-    if [ -z "${NIX_FIRST_BUILD_UID+x}" ] || [ -z "${NIX_BUILD_USER_NAME_TEMPLATE+x}" ]; then
-        failure "Internal error: System specific installer for $(uname) ($1) does not export required settings."
-    fi
-}
-
 welcome_to_nix() {
     local -r NIX_UID_RANGES="${NIX_FIRST_BUILD_UID}..$((NIX_FIRST_BUILD_UID + NIX_USER_COUNT - 1))"
     local -r RANGE_TEXT=$(echo -ne "${BLUE}(uids [${NIX_UID_RANGES}])${ESC}")
@@ -724,9 +718,7 @@ manager. This will happen in a few stages:
    if you are ready to continue.
 
 3. Create the system users ${RANGE_TEXT} and groups ${GROUP_TEXT}
-   that the Nix daemon uses to run builds. To create system users
-   in a different range, exit and run this tool again with
-   NIX_FIRST_BUILD_UID set.
+   that the Nix daemon uses to run builds.
 
 4. Perform the basic installation of the Nix files daemon.
 
@@ -968,16 +960,13 @@ main() {
     if is_os_darwin; then
         # shellcheck source=./install-darwin-multi-user.sh
         . "$EXTRACTED_NIX_PATH/install-darwin-multi-user.sh"
-        check_required_system_specific_settings "install-darwin-multi-user.sh"
     elif is_os_linux; then
         # shellcheck source=./install-systemd-multi-user.sh
         . "$EXTRACTED_NIX_PATH/install-systemd-multi-user.sh" # most of this works on non-systemd distros also
-        check_required_system_specific_settings "install-systemd-multi-user.sh"
     else
         failure "Sorry, I don't know what to do on $(uname)"
     fi
 
-
     welcome_to_nix
 
     if ! is_root; then

scripts/install-systemd-multi-user.sh

@@ -3,10 +3,6 @@
 set -eu
 set -o pipefail
 
-# System specific settings
-export NIX_FIRST_BUILD_UID="${NIX_FIRST_BUILD_UID:-30001}"
-export NIX_BUILD_USER_NAME_TEMPLATE="nixbld%d"
-
 readonly SERVICE_SRC=/lib/systemd/system/nix-daemon.service
 readonly SERVICE_DEST=/etc/systemd/system/nix-daemon.service
 

scripts/nix-profile-daemon.fish.in

@@ -19,14 +19,6 @@ set __ETC_PROFILE_NIX_SOURCED 1
 
 set --export NIX_PROFILES "@localstatedir@/nix/profiles/default $HOME/.nix-profile"
 
-# Populate bash completions, .desktop files, etc
-if test -z "$XDG_DATA_DIRS"
-    # According to XDG spec the default is /usr/local/share:/usr/share, don't set something that prevents that default
-    set --export XDG_DATA_DIRS "/usr/local/share:/usr/share:/nix/var/nix/profiles/default/share"
-else
-    set --export XDG_DATA_DIRS "$XDG_DATA_DIRS:/nix/var/nix/profiles/default/share"
-end
-
 # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
 if test -n "$NIX_SSH_CERT_FILE"
   : # Allow users to override the NIX_SSL_CERT_FILE

scripts/nix-profile-daemon.sh.in

@@ -30,14 +30,6 @@ fi
 
 export NIX_PROFILES="@localstatedir@/nix/profiles/default $NIX_LINK"
 
-# Populate bash completions, .desktop files, etc
-if [ -z "${XDG_DATA_DIRS-}" ]; then
-    # According to XDG spec the default is /usr/local/share:/usr/share, don't set something that prevents that default
-    export XDG_DATA_DIRS="/usr/local/share:/usr/share:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-else
-    export XDG_DATA_DIRS="$XDG_DATA_DIRS:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-fi
-
 # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
 if [ -n "${NIX_SSL_CERT_FILE:-}" ]; then
     : # Allow users to override the NIX_SSL_CERT_FILE

scripts/nix-profile.fish.in

@@ -20,14 +20,6 @@ if test -n "$HOME" && test -n "$USER"
     # This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
     set --export NIX_PROFILES "@localstatedir@/nix/profiles/default $HOME/.nix-profile"
 
-    # Populate bash completions, .desktop files, etc
-    if test -z "$XDG_DATA_DIRS"
-        # According to XDG spec the default is /usr/local/share:/usr/share, don't set something that prevents that default
-        set --export XDG_DATA_DIRS "/usr/local/share:/usr/share:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-    else
-        set --export XDG_DATA_DIRS "$XDG_DATA_DIRS:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-    end
-
     # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
     if test -n "$NIX_SSH_CERT_FILE"
         : # Allow users to override the NIX_SSL_CERT_FILE

scripts/nix-profile.sh.in

@@ -32,14 +32,6 @@ if [ -n "$HOME" ] && [ -n "$USER" ]; then
     # This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
     export NIX_PROFILES="@localstatedir@/nix/profiles/default $NIX_LINK"
 
-    # Populate bash completions, .desktop files, etc
-    if [ -z "${XDG_DATA_DIRS-}" ]; then
-        # According to XDG spec the default is /usr/local/share:/usr/share, don't set something that prevents that default
-        export XDG_DATA_DIRS="/usr/local/share:/usr/share:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-    else
-        export XDG_DATA_DIRS="$XDG_DATA_DIRS:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-    fi
-
     # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
     if [ -e /etc/ssl/certs/ca-certificates.crt ]; then # NixOS, Ubuntu, Debian, Gentoo, Arch
         export NIX_SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt

src/build-remote/build-remote.cc

@@ -137,8 +137,11 @@ static int main_build_remote(int argc, char * * argv)
                 for (auto & m : machines) {
                     debug("considering building on remote machine '%s'", m.storeUri);
 
-                    if (m.enabled &&
-                        m.systemSupported(neededSystem) &&
+                    if (m.enabled
+                        && (neededSystem == "builtin"
+                            || std::find(m.systemTypes.begin(),
+                                m.systemTypes.end(),
+                                neededSystem) != m.systemTypes.end()) &&
                         m.allSupported(requiredFeatures) &&
                         m.mandatoryMet(requiredFeatures))
                     {
@@ -202,7 +205,7 @@ static int main_build_remote(int argc, char * * argv)
                         else
                             drvstr = "<unknown>";
 
-                        auto error = HintFmt(errorText);
+                        auto error = hintformat(errorText);
                         error
                             % drvstr
                             % neededSystem
@@ -211,7 +214,7 @@ static int main_build_remote(int argc, char * * argv)
 
                         for (auto & m : machines)
                             error
-                                % concatStringsSep<StringSet>(", ", m.systemTypes)
+                                % concatStringsSep<std::vector<std::string>>(", ", m.systemTypes)
                                 % m.maxJobs
                                 % concatStringsSep<StringSet>(", ", m.supportedFeatures)
                                 % concatStringsSep<StringSet>(", ", m.mandatoryFeatures);

src/libcmd/built-path.cc

@@ -12,9 +12,9 @@ namespace nix {
     bool MY_TYPE ::operator COMPARATOR (const MY_TYPE & other) const \
     { \
         const MY_TYPE* me = this; \
-        auto fields1 = std::tie(*me->drvPath, me->FIELD); \
+        auto fields1 = std::make_tuple<const CHILD_TYPE &, const FIELD_TYPE &>(*me->drvPath, me->FIELD); \
         me = &other; \
-        auto fields2 = std::tie(*me->drvPath, me->FIELD); \
+        auto fields2 = std::make_tuple<const CHILD_TYPE &, const FIELD_TYPE &>(*me->drvPath, me->FIELD); \
         return fields1 COMPARATOR fields2; \
     }
 #define CMP(CHILD_TYPE, MY_TYPE, FIELD) \

src/libcmd/command.cc

@@ -98,7 +98,7 @@ EvalCommand::EvalCommand()
 EvalCommand::~EvalCommand()
 {
     if (evalState)
-        evalState->maybePrintStats();
+        evalState->printStats();
 }
 
 ref<Store> EvalCommand::getEvalStore()
@@ -175,7 +175,7 @@ void BuiltPathsCommand::run(ref<Store> store, Installables && installables)
             throw UsageError("'--all' does not expect arguments");
         // XXX: Only uses opaque paths, ignores all the realisations
         for (auto & p : store->queryAllValidPaths())
-            paths.emplace_back(BuiltPath::Opaque{p});
+            paths.push_back(BuiltPath::Opaque{p});
     } else {
         paths = Installable::toBuiltPaths(getEvalStore(), store, realiseMode, operateOn, installables);
         if (recursive) {
@@ -188,7 +188,7 @@ void BuiltPathsCommand::run(ref<Store> store, Installables && installables)
             }
             store->computeFSClosure(pathsRoots, pathsClosure);
             for (auto & path : pathsClosure)
-                paths.emplace_back(BuiltPath::Opaque{path});
+                paths.push_back(BuiltPath::Opaque{path});
         }
     }
 

src/libcmd/command.hh

@@ -34,28 +34,21 @@ struct NixMultiCommand : virtual MultiCommand, virtual Command
 // For the overloaded run methods
 #pragma GCC diagnostic ignored "-Woverloaded-virtual"
 
-/**
- * A command that requires a \ref Store "Nix store".
- */
+/* A command that requires a Nix store. */
 struct StoreCommand : virtual Command
 {
     StoreCommand();
     void run() override;
     ref<Store> getStore();
     virtual ref<Store> createStore();
-    /**
-     * Main entry point, with a `Store` provided
-     */
     virtual void run(ref<Store>) = 0;
 
 private:
     std::shared_ptr<Store> _store;
 };
 
-/**
- * A command that copies something between `--from` and `--to` \ref
- * Store stores.
- */
+/* A command that copies something between `--from` and `--to`
+   stores. */
 struct CopyCommand : virtual StoreCommand
 {
     std::string srcUri, dstUri;
@@ -67,9 +60,6 @@ struct CopyCommand : virtual StoreCommand
     ref<Store> getDstStore();
 };
 
-/**
- * A command that needs to evaluate Nix language expressions.
- */
 struct EvalCommand : virtual StoreCommand, MixEvalArgs
 {
     bool startReplOnEvalErrors = false;
@@ -89,10 +79,6 @@ private:
     std::shared_ptr<EvalState> evalState;
 };
 
-/**
- * A mixin class for commands that process flakes, adding a few standard
- * flake-related options/flags.
- */
 struct MixFlakeOptions : virtual Args, EvalCommand
 {
     flake::LockFlags lockFlags;
@@ -101,14 +87,6 @@ struct MixFlakeOptions : virtual Args, EvalCommand
 
     MixFlakeOptions();
 
-    /**
-     * The completion for some of these flags depends on the flake(s) in
-     * question.
-     *
-     * This method should be implemented to gather all flakerefs the
-     * command is operating with (presumably specified via some other
-     * arguments) so that the completions for these flags can use them.
-     */
     virtual std::vector<std::string> getFlakesForCompletion()
     { return {}; }
 
@@ -134,29 +112,15 @@ struct SourceExprCommand : virtual Args, MixFlakeOptions
 
     virtual Strings getDefaultFlakeAttrPathPrefixes();
 
-    /**
-     * Complete an installable from the given prefix.
-     */
     void completeInstallable(std::string_view prefix);
 };
 
-/**
- * A mixin class for commands that need a read-only flag.
- *
- * What exactly is "read-only" is unspecified, but it will usually be
- * the \ref Store "Nix store".
- */
 struct MixReadOnlyOption : virtual Args
 {
     MixReadOnlyOption();
 };
 
-/**
- * Like InstallablesCommand but the installables are not loaded.
- *
- * This is needed by `CmdRepl` which wants to load (and reload) the
- * installables itself.
- */
+/* Like InstallablesCommand but the installables are not loaded */
 struct RawInstallablesCommand : virtual Args, SourceExprCommand
 {
     RawInstallablesCommand();
@@ -165,7 +129,7 @@ struct RawInstallablesCommand : virtual Args, SourceExprCommand
 
     void run(ref<Store> store) override;
 
-    // FIXME make const after `CmdRepl`'s override is fixed up
+    // FIXME make const after CmdRepl's override is fixed up
     virtual void applyDefaultInstallables(std::vector<std::string> & rawInstallables);
 
     bool readFromStdIn = false;
@@ -176,11 +140,8 @@ private:
 
     std::vector<std::string> rawInstallables;
 };
-
-/**
- * A command that operates on a list of "installables", which can be
- * store paths, attribute paths, Nix expressions, etc.
- */
+/* A command that operates on a list of "installables", which can be
+   store paths, attribute paths, Nix expressions, etc. */
 struct InstallablesCommand : RawInstallablesCommand
 {
     virtual void run(ref<Store> store, Installables && installables) = 0;
@@ -188,9 +149,7 @@ struct InstallablesCommand : RawInstallablesCommand
     void run(ref<Store> store, std::vector<std::string> && rawInstallables) override;
 };
 
-/**
- * A command that operates on exactly one "installable".
- */
+/* A command that operates on exactly one "installable" */
 struct InstallableCommand : virtual Args, SourceExprCommand
 {
     InstallableCommand();
@@ -216,12 +175,7 @@ struct MixOperateOnOptions : virtual Args
     MixOperateOnOptions();
 };
 
-/**
- * A command that operates on zero or more extant store paths.
- *
- * If the argument the user passes is a some sort of recipe for a path
- * not yet built, it must be built first.
- */
+/* A command that operates on zero or more store paths. */
 struct BuiltPathsCommand : InstallablesCommand, virtual MixOperateOnOptions
 {
 private:
@@ -253,9 +207,7 @@ struct StorePathsCommand : public BuiltPathsCommand
     void run(ref<Store> store, BuiltPaths && paths) override;
 };
 
-/**
- * A command that operates on exactly one store path.
- */
+/* A command that operates on exactly one store path. */
 struct StorePathCommand : public StorePathsCommand
 {
     virtual void run(ref<Store> store, const StorePath & storePath) = 0;
@@ -263,9 +215,7 @@ struct StorePathCommand : public StorePathsCommand
     void run(ref<Store> store, StorePaths && storePaths) override;
 };
 
-/**
- * A helper class for registering \ref Command commands globally.
- */
+/* A helper class for registering commands globally. */
 struct RegisterCommand
 {
     typedef std::map<std::vector<std::string>, std::function<ref<Command>()>> Commands;
@@ -321,11 +271,7 @@ struct MixEnvironment : virtual Args {
 
     MixEnvironment();
 
-    /***
-     * Modify global environ based on `ignoreEnvironment`, `keep`, and
-     * `unset`. It's expected that exec will be called before this class
-     * goes out of scope, otherwise `environ` will become invalid.
-     */
+    /* Modify global environ based on ignoreEnvironment, keep, and unset. It's expected that exec will be called before this class goes out of scope, otherwise environ will become invalid. */
     void setEnviron();
 };
 

src/libcmd/editor-for.cc

@@ -1,6 +1,5 @@
 #include "util.hh"
 #include "editor-for.hh"
-#include "source-path.hh"
 
 namespace nix {
 

src/libcmd/editor-for.hh

@@ -2,7 +2,7 @@
 ///@file
 
 #include "types.hh"
-#include "source-path.hh"
+#include "input-accessor.hh"
 
 namespace nix {
 

src/libcmd/installable-flake.cc

@@ -47,7 +47,7 @@ Value * InstallableFlake::getFlakeOutputs(EvalState & state, const flake::Locked
     auto aOutputs = vFlake->attrs->get(state.symbols.create("outputs"));
     assert(aOutputs);
 
-    state.forceValue(*aOutputs->value, aOutputs->value->determinePos(noPos));
+    state.forceValue(*aOutputs->value, [&]() { return aOutputs->value->determinePos(noPos); });
 
     return aOutputs->value;
 }

src/libcmd/installable-value.cc

@@ -1,6 +1,5 @@
 #include "installable-value.hh"
 #include "eval-cache.hh"
-#include "fetch-to-store.hh"
 
 namespace nix {
 
@@ -45,7 +44,7 @@ ref<InstallableValue> InstallableValue::require(ref<Installable> installable)
 std::optional<DerivedPathWithInfo> InstallableValue::trySinglePathToDerivedPaths(Value & v, const PosIdx pos, std::string_view errorCtx)
 {
     if (v.type() == nPath) {
-        auto storePath = fetchToStore(*state->store, v.path());
+        auto storePath = v.path().fetchToStore(state->store);
         return {{
             .path = DerivedPath::Opaque {
                 .path = std::move(storePath),

src/libcmd/installables.cc

@@ -669,12 +669,12 @@ BuiltPaths Installable::toBuiltPaths(
 
         BuiltPaths res;
         for (auto & drvPath : Installable::toDerivations(store, installables, true))
-            res.emplace_back(BuiltPath::Opaque{drvPath});
+            res.push_back(BuiltPath::Opaque{drvPath});
         return res;
     }
 }
 
-StorePathSet Installable::toStorePathSet(
+StorePathSet Installable::toStorePaths(
     ref<Store> evalStore,
     ref<Store> store,
     Realise mode, OperateOn operateOn,
@@ -688,27 +688,13 @@ StorePathSet Installable::toStorePathSet(
     return outPaths;
 }
 
-StorePaths Installable::toStorePaths(
-    ref<Store> evalStore,
-    ref<Store> store,
-    Realise mode, OperateOn operateOn,
-    const Installables & installables)
-{
-    StorePaths outPaths;
-    for (auto & path : toBuiltPaths(evalStore, store, mode, operateOn, installables)) {
-        auto thisOutPaths = path.outPaths();
-        outPaths.insert(outPaths.end(), thisOutPaths.begin(), thisOutPaths.end());
-    }
-    return outPaths;
-}
-
 StorePath Installable::toStorePath(
     ref<Store> evalStore,
     ref<Store> store,
     Realise mode, OperateOn operateOn,
     ref<Installable> installable)
 {
-    auto paths = toStorePathSet(evalStore, store, mode, operateOn, {installable});
+    auto paths = toStorePaths(evalStore, store, mode, operateOn, {installable});
 
     if (paths.size() != 1)
         throw Error("argument '%s' should evaluate to one store path", installable->what());

src/libcmd/installables.hh

@@ -166,14 +166,7 @@ struct Installable
         const Installables & installables,
         BuildMode bMode = bmNormal);
 
-    static std::set<StorePath> toStorePathSet(
-        ref<Store> evalStore,
-        ref<Store> store,
-        Realise mode,
-        OperateOn operateOn,
-        const Installables & installables);
-
-    static std::vector<StorePath> toStorePaths(
+    static std::set<StorePath> toStorePaths(
         ref<Store> evalStore,
         ref<Store> store,
         Realise mode,

src/libcmd/local.mk

@@ -12,4 +12,4 @@ libcmd_LDFLAGS = $(EDITLINE_LIBS) $(LOWDOWN_LIBS) -pthread
 
 libcmd_LIBS = libstore libutil libexpr libmain libfetchers
 
-$(eval $(call install-file-in, $(buildprefix)$(d)/nix-cmd.pc, $(libdir)/pkgconfig, 0644))
+$(eval $(call install-file-in, $(d)/nix-cmd.pc, $(libdir)/pkgconfig, 0644))

src/libcmd/repl-interacter.cc

@@ -1,208 +0,0 @@
-#include <cstdio>
-#include <iostream>
-#include <string>
-
-#ifdef READLINE
-#include <readline/history.h>
-#include <readline/readline.h>
-#else
-// editline < 1.15.2 don't wrap their API for C++ usage
-// (added in https://github.com/troglobit/editline/commit/91398ceb3427b730995357e9d120539fb9bb7461).
-// This results in linker errors due to to name-mangling of editline C symbols.
-// For compatibility with these versions, we wrap the API here
-// (wrapping multiple times on newer versions is no problem).
-extern "C" {
-#include <editline.h>
-}
-#endif
-
-#include "signals.hh"
-#include "finally.hh"
-#include "repl-interacter.hh"
-#include "util.hh"
-#include "repl.hh"
-
-namespace nix {
-
-namespace {
-// Used to communicate to NixRepl::getLine whether a signal occurred in ::readline.
-volatile sig_atomic_t g_signal_received = 0;
-
-void sigintHandler(int signo)
-{
-    g_signal_received = signo;
-}
-};
-
-static detail::ReplCompleterMixin * curRepl; // ugly
-
-static char * completionCallback(char * s, int * match)
-{
-    auto possible = curRepl->completePrefix(s);
-    if (possible.size() == 1) {
-        *match = 1;
-        auto * res = strdup(possible.begin()->c_str() + strlen(s));
-        if (!res)
-            throw Error("allocation failure");
-        return res;
-    } else if (possible.size() > 1) {
-        auto checkAllHaveSameAt = [&](size_t pos) {
-            auto & first = *possible.begin();
-            for (auto & p : possible) {
-                if (p.size() <= pos || p[pos] != first[pos])
-                    return false;
-            }
-            return true;
-        };
-        size_t start = strlen(s);
-        size_t len = 0;
-        while (checkAllHaveSameAt(start + len))
-            ++len;
-        if (len > 0) {
-            *match = 1;
-            auto * res = strdup(std::string(*possible.begin(), start, len).c_str());
-            if (!res)
-                throw Error("allocation failure");
-            return res;
-        }
-    }
-
-    *match = 0;
-    return nullptr;
-}
-
-static int listPossibleCallback(char * s, char *** avp)
-{
-    auto possible = curRepl->completePrefix(s);
-
-    if (possible.size() > (INT_MAX / sizeof(char *)))
-        throw Error("too many completions");
-
-    int ac = 0;
-    char ** vp = nullptr;
-
-    auto check = [&](auto * p) {
-        if (!p) {
-            if (vp) {
-                while (--ac >= 0)
-                    free(vp[ac]);
-                free(vp);
-            }
-            throw Error("allocation failure");
-        }
-        return p;
-    };
-
-    vp = check((char **) malloc(possible.size() * sizeof(char *)));
-
-    for (auto & p : possible)
-        vp[ac++] = check(strdup(p.c_str()));
-
-    *avp = vp;
-
-    return ac;
-}
-
-ReadlineLikeInteracter::Guard ReadlineLikeInteracter::init(detail::ReplCompleterMixin * repl)
-{
-    // Allow nix-repl specific settings in .inputrc
-    rl_readline_name = "nix-repl";
-    try {
-        createDirs(dirOf(historyFile));
-    } catch (SysError & e) {
-        logWarning(e.info());
-    }
-#ifndef READLINE
-    el_hist_size = 1000;
-#endif
-    read_history(historyFile.c_str());
-    auto oldRepl = curRepl;
-    curRepl = repl;
-    Guard restoreRepl([oldRepl] { curRepl = oldRepl; });
-#ifndef READLINE
-    rl_set_complete_func(completionCallback);
-    rl_set_list_possib_func(listPossibleCallback);
-#endif
-    return restoreRepl;
-}
-
-static constexpr const char * promptForType(ReplPromptType promptType)
-{
-    switch (promptType) {
-    case ReplPromptType::ReplPrompt:
-        return "nix-repl> ";
-    case ReplPromptType::ContinuationPrompt:
-        return "          ";
-    }
-    assert(false);
-}
-
-bool ReadlineLikeInteracter::getLine(std::string & input, ReplPromptType promptType)
-{
-    struct sigaction act, old;
-    sigset_t savedSignalMask, set;
-
-    auto setupSignals = [&]() {
-        act.sa_handler = sigintHandler;
-        sigfillset(&act.sa_mask);
-        act.sa_flags = 0;
-        if (sigaction(SIGINT, &act, &old))
-            throw SysError("installing handler for SIGINT");
-
-        sigemptyset(&set);
-        sigaddset(&set, SIGINT);
-        if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask))
-            throw SysError("unblocking SIGINT");
-    };
-    auto restoreSignals = [&]() {
-        if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr))
-            throw SysError("restoring signals");
-
-        if (sigaction(SIGINT, &old, 0))
-            throw SysError("restoring handler for SIGINT");
-    };
-
-    setupSignals();
-    char * s = readline(promptForType(promptType));
-    Finally doFree([&]() { free(s); });
-    restoreSignals();
-
-    if (g_signal_received) {
-        g_signal_received = 0;
-        input.clear();
-        return true;
-    }
-
-    if (!s)
-        return false;
-    input += s;
-    input += '\n';
-    return true;
-}
-
-ReadlineLikeInteracter::~ReadlineLikeInteracter()
-{
-    write_history(historyFile.c_str());
-}
-
-AutomationInteracter::Guard AutomationInteracter::init(detail::ReplCompleterMixin *)
-{
-    return Guard([] {});
-}
-
-// ASCII ENQ character
-constexpr const char * automationPrompt = "\x05";
-
-bool AutomationInteracter::getLine(std::string & input, ReplPromptType promptType)
-{
-    std::cout << std::unitbuf;
-    std::cout << automationPrompt;
-    if (!std::getline(std::cin, input)) {
-        // reset failure bits on EOF
-        std::cin.clear();
-        return false;
-    }
-    return true;
-}
-
-};

src/libcmd/repl-interacter.hh

@@ -1,57 +0,0 @@
-#pragma once
-/// @file
-
-#include "finally.hh"
-#include "types.hh"
-#include <functional>
-#include <string>
-
-namespace nix {
-
-namespace detail {
-/** Provides the completion hooks for the repl, without exposing its complete
- * internals. */
-struct ReplCompleterMixin {
-    virtual StringSet completePrefix(const std::string & prefix) = 0;
-};
-};
-
-enum class ReplPromptType {
-    ReplPrompt,
-    ContinuationPrompt,
-};
-
-class ReplInteracter
-{
-public:
-    using Guard = Finally<std::function<void()>>;
-
-    virtual Guard init(detail::ReplCompleterMixin * repl) = 0;
-    /** Returns a boolean of whether the interacter got EOF */
-    virtual bool getLine(std::string & input, ReplPromptType promptType) = 0;
-    virtual ~ReplInteracter(){};
-};
-
-class ReadlineLikeInteracter : public virtual ReplInteracter
-{
-    std::string historyFile;
-public:
-    ReadlineLikeInteracter(std::string historyFile)
-        : historyFile(historyFile)
-    {
-    }
-    virtual Guard init(detail::ReplCompleterMixin * repl) override;
-    virtual bool getLine(std::string & input, ReplPromptType promptType) override;
-    virtual ~ReadlineLikeInteracter() override;
-};
-
-class AutomationInteracter : public virtual ReplInteracter
-{
-public:
-    AutomationInteracter() = default;
-    virtual Guard init(detail::ReplCompleterMixin * repl) override;
-    virtual bool getLine(std::string & input, ReplPromptType promptType) override;
-    virtual ~AutomationInteracter() override = default;
-};
-
-};

src/libcmd/repl.cc

@@ -3,8 +3,22 @@
 #include <cstring>
 #include <climits>
 
-#include "box_ptr.hh"
-#include "repl-interacter.hh"
+#include <setjmp.h>
+
+#ifdef READLINE
+#include <readline/history.h>
+#include <readline/readline.h>
+#else
+// editline < 1.15.2 don't wrap their API for C++ usage
+// (added in https://github.com/troglobit/editline/commit/91398ceb3427b730995357e9d120539fb9bb7461).
+// This results in linker errors due to to name-mangling of editline C symbols.
+// For compatibility with these versions, we wrap the API here
+// (wrapping multiple times on newer versions is no problem).
+extern "C" {
+#include <editline.h>
+}
+#endif
+
 #include "repl.hh"
 
 #include "ansicolor.hh"
@@ -14,7 +28,6 @@
 #include "eval-inline.hh"
 #include "eval-settings.hh"
 #include "attr-path.hh"
-#include "signals.hh"
 #include "store-api.hh"
 #include "log-store.hh"
 #include "common-eval-args.hh"
@@ -27,7 +40,7 @@
 #include "finally.hh"
 #include "markdown.hh"
 #include "local-fs-store.hh"
-#include "signals.hh"
+#include "progress-bar.hh"
 #include "print.hh"
 
 #if HAVE_BOEHMGC
@@ -37,30 +50,8 @@
 
 namespace nix {
 
-/**
- * Returned by `NixRepl::processLine`.
- */
-enum class ProcessLineResult {
-    /**
-     * The user exited with `:quit`. The REPL should exit. The surrounding
-     * program or evaluation (e.g., if the REPL was acting as the debugger)
-     * should also exit.
-     */
-    Quit,
-    /**
-     * The user exited with `:continue`. The REPL should exit, but the program
-     * should continue running.
-     */
-    Continue,
-    /**
-     * The user did not exit. The REPL should request another line of input.
-     */
-    PromptAgain,
-};
-
 struct NixRepl
     : AbstractNixRepl
-    , detail::ReplCompleterMixin
     #if HAVE_BOEHMGC
     , gc
     #endif
@@ -76,18 +67,19 @@ struct NixRepl
     int displ;
     StringSet varNames;
 
-    box_ptr<ReplInteracter> interacter;
+    const Path historyFile;
 
     NixRepl(const SearchPath & searchPath, nix::ref<Store> store,ref<EvalState> state,
             std::function<AnnotatedValues()> getValues);
-    virtual ~NixRepl() = default;
+    virtual ~NixRepl();
 
-    ReplExitStatus mainLoop() override;
+    void mainLoop() override;
     void initEnv() override;
 
-    virtual StringSet completePrefix(const std::string & prefix) override;
+    StringSet completePrefix(const std::string & prefix);
+    bool getLine(std::string & input, const std::string & prompt);
     StorePath getDerivationPath(Value & v);
-    ProcessLineResult processLine(std::string line);
+    bool processLine(std::string line);
 
     void loadFile(const Path & path);
     void loadFlake(const std::string & flakeRef);
@@ -99,18 +91,9 @@ struct NixRepl
     void evalString(std::string s, Value & v);
     void loadDebugTraceEnv(DebugTrace & dt);
 
-    void printValue(std::ostream & str,
-                              Value & v,
-                              unsigned int maxDepth = std::numeric_limits<unsigned int>::max())
-    {
-        ::nix::printValue(*state, str, v, PrintOptions {
-            .ansiColors = true,
-            .force = true,
-            .derivationPaths = true,
-            .maxDepth = maxDepth,
-            .prettyIndent = 2
-        });
-    }
+    typedef std::set<Value *> ValuesSeen;
+    std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth);
+    std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen);
 };
 
 std::string removeWhitespace(std::string s)
@@ -121,23 +104,23 @@ std::string removeWhitespace(std::string s)
     return s;
 }
 
-static box_ptr<ReplInteracter> makeInteracter() {
-    if (experimentalFeatureSettings.isEnabled(Xp::ReplAutomation))
-        return make_box_ptr<AutomationInteracter>();
-    else
-        return make_box_ptr<ReadlineLikeInteracter>(getDataDir() + "/nix/repl-history");
-}
 
 NixRepl::NixRepl(const SearchPath & searchPath, nix::ref<Store> store, ref<EvalState> state,
             std::function<NixRepl::AnnotatedValues()> getValues)
     : AbstractNixRepl(state)
     , debugTraceIndex(0)
     , getValues(getValues)
-    , staticEnv(new StaticEnv(nullptr, state->staticBaseEnv.get()))
-    , interacter(makeInteracter())
+    , staticEnv(new StaticEnv(false, state->staticBaseEnv.get()))
+    , historyFile(getDataDir() + "/nix/repl-history")
 {
 }
 
+
+NixRepl::~NixRepl()
+{
+    write_history(historyFile.c_str());
+}
+
 void runNix(Path program, const Strings & args,
     const std::optional<std::string> & input = {})
 {
@@ -154,6 +137,79 @@ void runNix(Path program, const Strings & args,
     return;
 }
 
+static NixRepl * curRepl; // ugly
+
+static char * completionCallback(char * s, int *match) {
+  auto possible = curRepl->completePrefix(s);
+  if (possible.size() == 1) {
+    *match = 1;
+    auto *res = strdup(possible.begin()->c_str() + strlen(s));
+    if (!res) throw Error("allocation failure");
+    return res;
+  } else if (possible.size() > 1) {
+    auto checkAllHaveSameAt = [&](size_t pos) {
+      auto &first = *possible.begin();
+      for (auto &p : possible) {
+        if (p.size() <= pos || p[pos] != first[pos])
+          return false;
+      }
+      return true;
+    };
+    size_t start = strlen(s);
+    size_t len = 0;
+    while (checkAllHaveSameAt(start + len)) ++len;
+    if (len > 0) {
+      *match = 1;
+      auto *res = strdup(std::string(*possible.begin(), start, len).c_str());
+      if (!res) throw Error("allocation failure");
+      return res;
+    }
+  }
+
+  *match = 0;
+  return nullptr;
+}
+
+static int listPossibleCallback(char *s, char ***avp) {
+  auto possible = curRepl->completePrefix(s);
+
+  if (possible.size() > (INT_MAX / sizeof(char*)))
+    throw Error("too many completions");
+
+  int ac = 0;
+  char **vp = nullptr;
+
+  auto check = [&](auto *p) {
+    if (!p) {
+      if (vp) {
+        while (--ac >= 0)
+          free(vp[ac]);
+        free(vp);
+      }
+      throw Error("allocation failure");
+    }
+    return p;
+  };
+
+  vp = check((char **)malloc(possible.size() * sizeof(char*)));
+
+  for (auto & p : possible)
+    vp[ac++] = check(strdup(p.c_str()));
+
+  *avp = vp;
+
+  return ac;
+}
+
+namespace {
+    // Used to communicate to NixRepl::getLine whether a signal occurred in ::readline.
+    volatile sig_atomic_t g_signal_received = 0;
+
+    void sigintHandler(int signo) {
+        g_signal_received = signo;
+    }
+}
+
 static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positions, const DebugTrace & dt)
 {
     if (dt.isError)
@@ -163,10 +219,10 @@ static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positi
     // prefer direct pos, but if noPos then try the expr.
     auto pos = dt.pos
         ? dt.pos
-        : positions[dt.expr.getPos() ? dt.expr.getPos() : noPos];
+        : static_cast<std::shared_ptr<AbstractPos>>(positions[dt.expr.getPos() ? dt.expr.getPos() : noPos]);
 
     if (pos) {
-        out << *pos;
+        out << pos;
         if (auto loc = pos->getCodeLines()) {
             out << "\n";
             printCodeLines(out, "", *pos, *loc);
@@ -177,51 +233,50 @@ static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positi
     return out;
 }
 
-static bool isFirstRepl = true;
-
-ReplExitStatus NixRepl::mainLoop()
+void NixRepl::mainLoop()
 {
-    if (isFirstRepl) {
-        std::string_view debuggerNotice = "";
-        if (state->debugRepl) {
-            debuggerNotice = " debugger";
-        }
-        notice("Nix %1%%2%\nType :? for help.", nixVersion, debuggerNotice);
-    }
-
-    isFirstRepl = false;
+    std::string error = ANSI_RED "error:" ANSI_NORMAL " ";
+    notice("Welcome to Nix " + nixVersion + ". Type :? for help.\n");
 
     loadFiles();
 
-    auto _guard = interacter->init(static_cast<detail::ReplCompleterMixin *>(this));
+    // Allow nix-repl specific settings in .inputrc
+    rl_readline_name = "nix-repl";
+    try {
+        createDirs(dirOf(historyFile));
+    } catch (SysError & e) {
+        logWarning(e.info());
+    }
+#ifndef READLINE
+    el_hist_size = 1000;
+#endif
+    read_history(historyFile.c_str());
+    auto oldRepl = curRepl;
+    curRepl = this;
+    Finally restoreRepl([&] { curRepl = oldRepl; });
+#ifndef READLINE
+    rl_set_complete_func(completionCallback);
+    rl_set_list_possib_func(listPossibleCallback);
+#endif
+
+    /* Stop the progress bar because it interferes with the display of
+       the repl. */
+    stopProgressBar();
 
     std::string input;
 
     while (true) {
-        // Hide the progress bar while waiting for user input, so that it won't interfere.
-        logger->pause();
         // When continuing input from previous lines, don't print a prompt, just align to the same
         // number of chars as the prompt.
-        if (!interacter->getLine(input, input.empty() ? ReplPromptType::ReplPrompt : ReplPromptType::ContinuationPrompt)) {
-            // Ctrl-D should exit the debugger.
+        if (!getLine(input, input.empty() ? "nix-repl> " : "          ")) {
+            // ctrl-D should exit the debugger.
             state->debugStop = false;
+            state->debugQuit = true;
             logger->cout("");
-            // TODO: Should Ctrl-D exit just the current debugger session or
-            // the entire program?
-            return ReplExitStatus::QuitAll;
+            break;
         }
-        logger->resume();
         try {
-            switch (processLine(input)) {
-                case ProcessLineResult::Quit:
-                    return ReplExitStatus::QuitAll;
-                case ProcessLineResult::Continue:
-                    return ReplExitStatus::Continue;
-                case ProcessLineResult::PromptAgain:
-                    break;
-                default:
-                    abort();
-            }
+            if (!removeWhitespace(input).empty() && !processLine(input)) return;
         } catch (ParseError & e) {
             if (e.msg().find("unexpected end of file") != std::string::npos) {
                 // For parse errors on incomplete input, we continue waiting for the next line of
@@ -251,6 +306,52 @@ ReplExitStatus NixRepl::mainLoop()
     }
 }
 
+
+bool NixRepl::getLine(std::string & input, const std::string & prompt)
+{
+    struct sigaction act, old;
+    sigset_t savedSignalMask, set;
+
+    auto setupSignals = [&]() {
+        act.sa_handler = sigintHandler;
+        sigfillset(&act.sa_mask);
+        act.sa_flags = 0;
+        if (sigaction(SIGINT, &act, &old))
+            throw SysError("installing handler for SIGINT");
+
+        sigemptyset(&set);
+        sigaddset(&set, SIGINT);
+        if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask))
+            throw SysError("unblocking SIGINT");
+    };
+    auto restoreSignals = [&]() {
+        if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr))
+            throw SysError("restoring signals");
+
+        if (sigaction(SIGINT, &old, 0))
+            throw SysError("restoring handler for SIGINT");
+    };
+
+    setupSignals();
+    Finally resetTerminal([&]() { rl_deprep_terminal(); });
+    char * s = readline(prompt.c_str());
+    Finally doFree([&]() { free(s); });
+    restoreSignals();
+
+    if (g_signal_received) {
+        g_signal_received = 0;
+        input.clear();
+        return true;
+    }
+
+    if (!s)
+      return false;
+    input += s;
+    input += '\n';
+    return true;
+}
+
+
 StringSet NixRepl::completePrefix(const std::string & prefix)
 {
     StringSet completions;
@@ -312,6 +413,8 @@ StringSet NixRepl::completePrefix(const std::string & prefix)
             // Quietly ignore parse errors.
         } catch (EvalError & e) {
             // Quietly ignore evaluation errors.
+        } catch (UndefinedVarError & e) {
+            // Quietly ignore undefined variable errors.
         } catch (BadURL & e) {
             // Quietly ignore BadURL flake-related errors.
         }
@@ -363,11 +466,10 @@ void NixRepl::loadDebugTraceEnv(DebugTrace & dt)
     }
 }
 
-ProcessLineResult NixRepl::processLine(std::string line)
+bool NixRepl::processLine(std::string line)
 {
     line = trim(line);
-    if (line.empty())
-        return ProcessLineResult::PromptAgain;
+    if (line == "") return true;
 
     _isInterrupted = false;
 
@@ -462,13 +564,13 @@ ProcessLineResult NixRepl::processLine(std::string line)
     else if (state->debugRepl && (command == ":s" || command == ":step")) {
         // set flag to stop at next DebugTrace; exit repl.
         state->debugStop = true;
-        return ProcessLineResult::Continue;
+        return false;
     }
 
     else if (state->debugRepl && (command == ":c" || command == ":continue")) {
         // set flag to run to next breakpoint or end of program; exit repl.
         state->debugStop = false;
-        return ProcessLineResult::Continue;
+        return false;
     }
 
     else if (command == ":a" || command == ":add") {
@@ -605,13 +707,13 @@ ProcessLineResult NixRepl::processLine(std::string line)
     else if (command == ":p" || command == ":print") {
         Value v;
         evalString(arg, v);
-        printValue(std::cout, v);
-        std::cout << std::endl;
+        printValue(std::cout, v, 1000000000) << std::endl;
     }
 
     else if (command == ":q" || command == ":quit") {
         state->debugStop = false;
-        return ProcessLineResult::Quit;
+        state->debugQuit = true;
+        return false;
     }
 
     else if (command == ":doc") {
@@ -667,12 +769,11 @@ ProcessLineResult NixRepl::processLine(std::string line)
         } else {
             Value v;
             evalString(line, v);
-            printValue(std::cout, v, 1);
-            std::cout << std::endl;
+            printValue(std::cout, v, 1) << std::endl;
         }
     }
 
-    return ProcessLineResult::PromptAgain;
+    return true;
 }
 
 void NixRepl::loadFile(const Path & path)
@@ -786,7 +887,145 @@ void NixRepl::evalString(std::string s, Value & v)
 {
     Expr * e = parseString(s);
     e->eval(*state, *env, v);
-    state->forceValue(v, v.determinePos(noPos));
+    state->forceValue(v, [&]() { return v.determinePos(noPos); });
+}
+
+
+std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth)
+{
+    ValuesSeen seen;
+    return printValue(str, v, maxDepth, seen);
+}
+
+
+
+
+// FIXME: lot of cut&paste from Nix's eval.cc.
+std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int maxDepth, ValuesSeen & seen)
+{
+    str.flush();
+    checkInterrupt();
+
+    state->forceValue(v, [&]() { return v.determinePos(noPos); });
+
+    switch (v.type()) {
+
+    case nInt:
+        str << ANSI_CYAN << v.integer << ANSI_NORMAL;
+        break;
+
+    case nBool:
+        str << ANSI_CYAN;
+        printLiteralBool(str, v.boolean);
+        str << ANSI_NORMAL;
+        break;
+
+    case nString:
+        str << ANSI_WARNING;
+        printLiteralString(str, v.string.s);
+        str << ANSI_NORMAL;
+        break;
+
+    case nPath:
+        str << ANSI_GREEN << v.path().to_string() << ANSI_NORMAL; // !!! escaping?
+        break;
+
+    case nNull:
+        str << ANSI_CYAN "null" ANSI_NORMAL;
+        break;
+
+    case nAttrs: {
+        seen.insert(&v);
+
+        bool isDrv = state->isDerivation(v);
+
+        if (isDrv) {
+            str << "«derivation ";
+            Bindings::iterator i = v.attrs->find(state->sDrvPath);
+            NixStringContext context;
+            if (i != v.attrs->end())
+                str << state->store->printStorePath(state->coerceToStorePath(i->pos, *i->value, context, "while evaluating the drvPath of a derivation"));
+            else
+                str << "???";
+            str << "»";
+        }
+
+        else if (maxDepth > 0) {
+            str << "{ ";
+
+            typedef std::map<std::string, Value *> Sorted;
+            Sorted sorted;
+            for (auto & i : *v.attrs)
+                sorted.emplace(state->symbols[i.name], i.value);
+
+            for (auto & i : sorted) {
+                printAttributeName(str, i.first);
+                str << " = ";
+                if (seen.count(i.second))
+                    str << "«repeated»";
+                else
+                    try {
+                        printValue(str, *i.second, maxDepth - 1, seen);
+                    } catch (AssertionError & e) {
+                        str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL;
+                    }
+                str << "; ";
+            }
+
+            str << "}";
+        } else
+            str << "{ ... }";
+
+        break;
+    }
+
+    case nList:
+        seen.insert(&v);
+
+        str << "[ ";
+        if (maxDepth > 0)
+            for (auto elem : v.listItems()) {
+                if (seen.count(elem))
+                    str << "«repeated»";
+                else
+                    try {
+                        printValue(str, *elem, maxDepth - 1, seen);
+                    } catch (AssertionError & e) {
+                        str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL;
+                    }
+                str << " ";
+            }
+        else
+            str << "... ";
+        str << "]";
+        break;
+
+    case nFunction:
+        if (v.isLambda()) {
+            std::ostringstream s;
+            s << state->positions[v.lambda.fun->pos];
+            str << ANSI_BLUE "«lambda @ " << filterANSIEscapes(s.str()) << "»" ANSI_NORMAL;
+        } else if (v.isPrimOp()) {
+            str << ANSI_MAGENTA "«primop»" ANSI_NORMAL;
+        } else if (v.isPrimOpApp()) {
+            str << ANSI_BLUE "«primop-app»" ANSI_NORMAL;
+        } else {
+            abort();
+        }
+        break;
+
+    case nFloat:
+        str << v.fpoint;
+        break;
+
+    case nThunk:
+    case nExternal:
+    default:
+        str << ANSI_RED "«unknown»" ANSI_NORMAL;
+        break;
+    }
+
+    return str;
 }
 
 
@@ -803,7 +1042,7 @@ std::unique_ptr<AbstractNixRepl> AbstractNixRepl::create(
 }
 
 
-ReplExitStatus AbstractNixRepl::runSimple(
+void AbstractNixRepl::runSimple(
     ref<EvalState> evalState,
     const ValMap & extraEnv)
 {
@@ -825,7 +1064,7 @@ ReplExitStatus AbstractNixRepl::runSimple(
     for (auto & [name, value] : extraEnv)
         repl->addVarToScope(repl->state->symbols.create(name), *value);
 
-    return repl->mainLoop();
+    repl->mainLoop();
 }
 
 }

src/libcmd/repl.hh

@@ -3,6 +3,11 @@
 
 #include "eval.hh"
 
+#if HAVE_BOEHMGC
+#define GC_INCLUDE_NEW
+#include <gc/gc_cpp.h>
+#endif
+
 namespace nix {
 
 struct AbstractNixRepl
@@ -23,13 +28,13 @@ struct AbstractNixRepl
         const SearchPath & searchPath, nix::ref<Store> store, ref<EvalState> state,
         std::function<AnnotatedValues()> getValues);
 
-    static ReplExitStatus runSimple(
+    static void runSimple(
         ref<EvalState> evalState,
         const ValMap & extraEnv);
 
     virtual void initEnv() = 0;
 
-    virtual ReplExitStatus mainLoop() = 0;
+    virtual void mainLoop() = 0;
 };
 
 }

src/libexpr/attr-path.cc

@@ -66,10 +66,10 @@ std::pair<Value *, PosIdx> findAlongAttrPath(EvalState & state, const std::strin
         if (!attrIndex) {
 
             if (v->type() != nAttrs)
-                state.error<TypeError>(
+                throw TypeError(
                     "the expression selected by the selection path '%1%' should be a set but is %2%",
                     attrPath,
-                    showType(*v)).debugThrow();
+                    showType(*v));
             if (attr.empty())
                 throw Error("empty attribute name in selection path '%1%'", attrPath);
 
@@ -89,10 +89,10 @@ std::pair<Value *, PosIdx> findAlongAttrPath(EvalState & state, const std::strin
         else {
 
             if (!v->isList())
-                state.error<TypeError>(
+                throw TypeError(
                     "the expression selected by the selection path '%1%' should be a list but is %2%",
                     attrPath,
-                    showType(*v)).debugThrow();
+                    showType(*v));
             if (*attrIndex >= v->listSize())
                 throw AttrPathNotFound("list index %1% in selection path '%2%' is out of range", *attrIndex, attrPath);
 

src/libexpr/eval-cache.cc

@@ -490,7 +490,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
                         if (forceErrors)
                             debug("reevaluating failed cached attribute '%s'", getAttrPathStr(name));
                         else
-                            throw CachedEvalError(root->state, "cached failure of attribute '%s'", getAttrPathStr(name));
+                            throw CachedEvalError("cached failure of attribute '%s'", getAttrPathStr(name));
                     } else
                         return std::make_shared<AttrCursor>(root,
                             std::make_pair(shared_from_this(), name), nullptr, std::move(attr));
@@ -499,7 +499,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
                 // evaluate to see whether 'name' exists
             } else
                 return nullptr;
-                //error<TypeError>("'%s' is not an attribute set", getAttrPathStr()).debugThrow();
+                //throw TypeError("'%s' is not an attribute set", getAttrPathStr());
         }
     }
 
@@ -507,7 +507,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
 
     if (v.type() != nAttrs)
         return nullptr;
-        //error<TypeError>("'%s' is not an attribute set", getAttrPathStr()).debugThrow();
+        //throw TypeError("'%s' is not an attribute set", getAttrPathStr());
 
     auto attr = v.attrs->get(name);
 
@@ -573,14 +573,14 @@ std::string AttrCursor::getString()
                 debug("using cached string attribute '%s'", getAttrPathStr());
                 return s->first;
             } else
-                root->state.error<TypeError>("'%s' is not a string", getAttrPathStr()).debugThrow();
+                root->state.error("'%s' is not a string", getAttrPathStr()).debugThrow<TypeError>();
         }
     }
 
     auto & v = forceValue();
 
     if (v.type() != nString && v.type() != nPath)
-        root->state.error<TypeError>("'%s' is not a string but %s", getAttrPathStr()).debugThrow();
+        root->state.error("'%s' is not a string but %s", getAttrPathStr()).debugThrow<TypeError>();
 
     return v.type() == nString ? v.string.s : v.path().to_string();
 }
@@ -615,7 +615,7 @@ string_t AttrCursor::getStringWithContext()
                     return *s;
                 }
             } else
-                root->state.error<TypeError>("'%s' is not a string", getAttrPathStr()).debugThrow();
+                root->state.error("'%s' is not a string", getAttrPathStr()).debugThrow<TypeError>();
         }
     }
 
@@ -629,7 +629,7 @@ string_t AttrCursor::getStringWithContext()
     else if (v.type() == nPath)
         return {v.path().to_string(), {}};
     else
-        root->state.error<TypeError>("'%s' is not a string but %s", getAttrPathStr()).debugThrow();
+        root->state.error("'%s' is not a string but %s", getAttrPathStr()).debugThrow<TypeError>();
 }
 
 bool AttrCursor::getBool()
@@ -642,14 +642,14 @@ bool AttrCursor::getBool()
                 debug("using cached Boolean attribute '%s'", getAttrPathStr());
                 return *b;
             } else
-                root->state.error<TypeError>("'%s' is not a Boolean", getAttrPathStr()).debugThrow();
+                root->state.error("'%s' is not a Boolean", getAttrPathStr()).debugThrow<TypeError>();
         }
     }
 
     auto & v = forceValue();
 
     if (v.type() != nBool)
-        root->state.error<TypeError>("'%s' is not a Boolean", getAttrPathStr()).debugThrow();
+        root->state.error("'%s' is not a Boolean", getAttrPathStr()).debugThrow<TypeError>();
 
     return v.boolean;
 }
@@ -664,14 +664,14 @@ NixInt AttrCursor::getInt()
                 debug("using cached integer attribute '%s'", getAttrPathStr());
                 return i->x;
             } else
-                root->state.error<TypeError>("'%s' is not an integer", getAttrPathStr()).debugThrow();
+                throw TypeError("'%s' is not an integer", getAttrPathStr());
         }
     }
 
     auto & v = forceValue();
 
     if (v.type() != nInt)
-        root->state.error<TypeError>("'%s' is not an integer", getAttrPathStr()).debugThrow();
+        throw TypeError("'%s' is not an integer", getAttrPathStr());
 
     return v.integer;
 }
@@ -686,7 +686,7 @@ std::vector<std::string> AttrCursor::getListOfStrings()
                 debug("using cached list of strings attribute '%s'", getAttrPathStr());
                 return *l;
             } else
-                root->state.error<TypeError>("'%s' is not a list of strings", getAttrPathStr()).debugThrow();
+                throw TypeError("'%s' is not a list of strings", getAttrPathStr());
         }
     }
 
@@ -696,7 +696,7 @@ std::vector<std::string> AttrCursor::getListOfStrings()
     root->state.forceValue(v, noPos);
 
     if (v.type() != nList)
-        root->state.error<TypeError>("'%s' is not a list", getAttrPathStr()).debugThrow();
+        throw TypeError("'%s' is not a list", getAttrPathStr());
 
     std::vector<std::string> res;
 
@@ -719,14 +719,14 @@ std::vector<Symbol> AttrCursor::getAttrs()
                 debug("using cached attrset attribute '%s'", getAttrPathStr());
                 return *attrs;
             } else
-                root->state.error<TypeError>("'%s' is not an attribute set", getAttrPathStr()).debugThrow();
+                root->state.error("'%s' is not an attribute set", getAttrPathStr()).debugThrow<TypeError>();
         }
     }
 
     auto & v = forceValue();
 
     if (v.type() != nAttrs)
-        root->state.error<TypeError>("'%s' is not an attribute set", getAttrPathStr()).debugThrow();
+        root->state.error("'%s' is not an attribute set", getAttrPathStr()).debugThrow<TypeError>();
 
     std::vector<Symbol> attrs;
     for (auto & attr : *getValue().attrs)

src/libexpr/eval-cache.hh

@@ -10,6 +10,8 @@
 
 namespace nix::eval_cache {
 
+MakeError(CachedEvalError, EvalError);
+
 struct AttrDb;
 class AttrCursor;
 

src/libexpr/eval-error.cc

@@ -1,105 +0,0 @@
-#include "eval-error.hh"
-#include "eval.hh"
-#include "value.hh"
-
-namespace nix {
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::withExitStatus(unsigned int exitStatus)
-{
-    error.withExitStatus(exitStatus);
-    return *this;
-}
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::atPos(PosIdx pos)
-{
-    error.err.pos = error.state.positions[pos];
-    return *this;
-}
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::atPos(Value & value, PosIdx fallback)
-{
-    return atPos(value.determinePos(fallback));
-}
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::withTrace(PosIdx pos, const std::string_view text)
-{
-    error.err.traces.push_front(
-        Trace{.pos = error.state.positions[pos], .hint = HintFmt(std::string(text))});
-    return *this;
-}
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::withSuggestions(Suggestions & s)
-{
-    error.err.suggestions = s;
-    return *this;
-}
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::withFrame(const Env & env, const Expr & expr)
-{
-    // NOTE: This is abusing side-effects.
-    // TODO: check compatibility with nested debugger calls.
-    // TODO: What side-effects??
-    error.state.debugTraces.push_front(DebugTrace{
-        .pos = error.state.positions[expr.getPos()],
-        .expr = expr,
-        .env = env,
-        .hint = HintFmt("Fake frame for debugging purposes"),
-        .isError = true});
-    return *this;
-}
-
-template<class T>
-EvalErrorBuilder<T> & EvalErrorBuilder<T>::addTrace(PosIdx pos, HintFmt hint)
-{
-    error.addTrace(error.state.positions[pos], hint);
-    return *this;
-}
-
-template<class T>
-template<typename... Args>
-EvalErrorBuilder<T> &
-EvalErrorBuilder<T>::addTrace(PosIdx pos, std::string_view formatString, const Args &... formatArgs)
-{
-
-    addTrace(error.state.positions[pos], HintFmt(std::string(formatString), formatArgs...));
-    return *this;
-}
-
-template<class T>
-void EvalErrorBuilder<T>::debugThrow()
-{
-    if (error.state.debugRepl && !error.state.debugTraces.empty()) {
-        const DebugTrace & last = error.state.debugTraces.front();
-        const Env * env = &last.env;
-        const Expr * expr = &last.expr;
-        error.state.runDebugRepl(&error, *env, *expr);
-    }
-
-    // `EvalState` is the only class that can construct an `EvalErrorBuilder`,
-    // and it does so in dynamic storage. This is the final method called on
-    // any such instance and must delete itself before throwing the underlying
-    // error.
-    auto error = std::move(this->error);
-    delete this;
-
-    throw error;
-}
-
-template class EvalErrorBuilder<EvalError>;
-template class EvalErrorBuilder<AssertionError>;
-template class EvalErrorBuilder<ThrownError>;
-template class EvalErrorBuilder<Abort>;
-template class EvalErrorBuilder<TypeError>;
-template class EvalErrorBuilder<UndefinedVarError>;
-template class EvalErrorBuilder<MissingArgumentError>;
-template class EvalErrorBuilder<InfiniteRecursionError>;
-template class EvalErrorBuilder<CachedEvalError>;
-template class EvalErrorBuilder<InvalidPathError>;
-
-}

src/libexpr/eval-error.hh

@@ -1,105 +0,0 @@
-#pragma once
-
-#include <algorithm>
-
-#include "error.hh"
-#include "pos-idx.hh"
-
-namespace nix {
-
-struct Env;
-struct Expr;
-struct Value;
-
-class EvalState;
-template<class T>
-class EvalErrorBuilder;
-
-class EvalError : public Error
-{
-    template<class T>
-    friend class EvalErrorBuilder;
-public:
-    EvalState & state;
-
-    EvalError(EvalState & state, ErrorInfo && errorInfo)
-        : Error(errorInfo)
-        , state(state)
-    {
-    }
-
-    template<typename... Args>
-    explicit EvalError(EvalState & state, const std::string & formatString, const Args &... formatArgs)
-        : Error(formatString, formatArgs...)
-        , state(state)
-    {
-    }
-};
-
-MakeError(ParseError, Error);
-MakeError(AssertionError, EvalError);
-MakeError(ThrownError, AssertionError);
-MakeError(Abort, EvalError);
-MakeError(TypeError, EvalError);
-MakeError(UndefinedVarError, EvalError);
-MakeError(MissingArgumentError, EvalError);
-MakeError(RestrictedPathError, Error);
-MakeError(CachedEvalError, EvalError);
-MakeError(InfiniteRecursionError, EvalError);
-
-struct InvalidPathError : public EvalError
-{
-public:
-    Path path;
-    InvalidPathError(EvalState & state, const Path & path)
-        : EvalError(state, "path '%s' is not valid", path)
-    {
-    }
-};
-
-/**
- * `EvalErrorBuilder`s may only be constructed by `EvalState`. The `debugThrow`
- * method must be the final method in any such `EvalErrorBuilder` usage, and it
- * handles deleting the object.
- */
-template<class T>
-class EvalErrorBuilder final
-{
-    friend class EvalState;
-
-    template<typename... Args>
-    explicit EvalErrorBuilder(EvalState & state, const Args &... args)
-        : error(T(state, args...))
-    {
-    }
-
-public:
-    T error;
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withExitStatus(unsigned int exitStatus);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & atPos(PosIdx pos);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & atPos(Value & value, PosIdx fallback = noPos);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withTrace(PosIdx pos, const std::string_view text);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withFrameTrace(PosIdx pos, const std::string_view text);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withSuggestions(Suggestions & s);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withFrame(const Env & e, const Expr & ex);
-
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & addTrace(PosIdx pos, HintFmt hint);
-
-    template<typename... Args>
-    [[nodiscard, gnu::noinline]] EvalErrorBuilder<T> &
-    addTrace(PosIdx pos, std::string_view formatString, const Args &... formatArgs);
-
-    /**
-     * Delete the `EvalErrorBuilder` and throw the underlying exception.
-     */
-    [[gnu::noinline, gnu::noreturn]] void debugThrow();
-};
-
-}

src/libexpr/eval-inline.hh

@@ -1,9 +1,7 @@
 #pragma once
 ///@file
 
-#include "print.hh"
 #include "eval.hh"
-#include "eval-error.hh"
 
 namespace nix {
 
@@ -75,6 +73,8 @@ Env & EvalState::allocEnv(size_t size)
 #endif
         env = (Env *) allocBytes(sizeof(Env) + size * sizeof(Value *));
 
+    env->type = Env::Plain;
+
     /* We assume that env->values has been cleared by the allocator; maybeThunk() and lookupVar fromWith expect this. */
 
     return *env;
@@ -83,6 +83,13 @@ Env & EvalState::allocEnv(size_t size)
 
 [[gnu::always_inline]]
 void EvalState::forceValue(Value & v, const PosIdx pos)
+{
+    forceValue(v, [&]() { return pos; });
+}
+
+
+template<typename Callable>
+void EvalState::forceValue(Value & v, Callable getPos)
 {
     if (v.isThunk()) {
         Env * env = v.thunk.env;
@@ -93,12 +100,13 @@ void EvalState::forceValue(Value & v, const PosIdx pos)
             expr->eval(*this, *env, v);
         } catch (...) {
             v.mkThunk(env, expr);
-            tryFixupBlackHolePos(v, pos);
             throw;
         }
     }
     else if (v.isApp())
-        callFunction(*v.app.left, *v.app.right, v, pos);
+        callFunction(*v.app.left, *v.app.right, v, noPos);
+    else if (v.isBlackhole())
+        error("infinite recursion encountered").atPos(getPos()).template debugThrow<EvalError>();
 }
 
 
@@ -113,14 +121,10 @@ template <typename Callable>
 [[gnu::always_inline]]
 inline void EvalState::forceAttrs(Value & v, Callable getPos, std::string_view errorCtx)
 {
-    PosIdx pos = getPos();
-    forceValue(v, pos);
+    forceValue(v, noPos);
     if (v.type() != nAttrs) {
-        error<TypeError>(
-            "expected a set but found %1%: %2%",
-            showType(v),
-            ValuePrinter(*this, v, errorPrintOptions)
-        ).withTrace(pos, errorCtx).debugThrow();
+        PosIdx pos = getPos();
+        error("value is %1% while a set was expected", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>();
     }
 }
 
@@ -128,13 +132,9 @@ inline void EvalState::forceAttrs(Value & v, Callable getPos, std::string_view e
 [[gnu::always_inline]]
 inline void EvalState::forceList(Value & v, const PosIdx pos, std::string_view errorCtx)
 {
-    forceValue(v, pos);
+    forceValue(v, noPos);
     if (!v.isList()) {
-        error<TypeError>(
-            "expected a list but found %1%: %2%",
-            showType(v),
-            ValuePrinter(*this, v, errorPrintOptions)
-        ).withTrace(pos, errorCtx).debugThrow();
+        error("value is %1% while a list was expected", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>();
     }
 }
 

src/libexpr/eval-settings.cc

@@ -88,12 +88,6 @@ std::string EvalSettings::resolvePseudoUrl(std::string_view url)
         return std::string(url);
 }
 
-const std::string & EvalSettings::getCurrentSystem()
-{
-    const auto & evalSystem = currentSystem.get();
-    return evalSystem != "" ? evalSystem : settings.thisSystem.get();
-}
-
 EvalSettings evalSettings;
 
 static GlobalConfig::Register rEvalSettings(&evalSettings);

src/libexpr/eval-settings.hh

@@ -25,26 +25,6 @@ struct EvalSettings : Config
           [`builtins.nixPath`](@docroot@/language/builtin-constants.md#builtins-nixPath).
         )"};
 
-    Setting<std::string> currentSystem{
-        this, "", "eval-system",
-        R"(
-          This option defines
-          [`builtins.currentSystem`](@docroot@/language/builtin-constants.md#builtins-currentSystem)
-          in the Nix language if it is set as a non-empty string.
-          Otherwise, if it is defined as the empty string (the default), the value of the
-          [`system` ](#conf-system)
-          configuration setting is used instead.
-
-          Unlike `system`, this setting does not change what kind of derivations can be built locally.
-          This is useful for evaluating Nix code on one system to produce derivations to be built on another type of system.
-        )"};
-
-    /**
-     * Implements the `eval-system` vs `system` defaulting logic
-     * described for `eval-system`.
-     */
-    const std::string & getCurrentSystem();
-
     Setting<bool> restrictEval{
         this, false, "restrict-eval",
         R"(
@@ -111,19 +91,6 @@ struct EvalSettings : Config
 
     Setting<bool> traceVerbose{this, false, "trace-verbose",
         "Whether `builtins.traceVerbose` should trace its first argument when evaluated."};
-
-    Setting<unsigned int> maxCallDepth{this, 10000, "max-call-depth",
-        "The maximum function call depth to allow before erroring."};
-
-    Setting<bool> builtinsTraceDebugger{this, false, "debugger-on-trace",
-        R"(
-          If set to true and the `--debugger` flag is given,
-          [`builtins.trace`](@docroot@/language/builtins.md#builtins-trace) will
-          enter the debugger like
-          [`builtins.break`](@docroot@/language/builtins.md#builtins-break).
-
-          This is useful for debugging warnings in third-party Nix code.
-        )"};
 };
 
 extern EvalSettings evalSettings;

src/libexpr/eval.hh

@@ -2,7 +2,6 @@
 ///@file
 
 #include "attr-set.hh"
-#include "eval-error.hh"
 #include "types.hh"
 #include "value.hh"
 #include "nixexpr.hh"
@@ -11,7 +10,6 @@
 #include "experimental-features.hh"
 #include "input-accessor.hh"
 #include "search-path.hh"
-#include "repl-exit-status.hh"
 
 #include <map>
 #include <optional>
@@ -20,12 +18,6 @@
 
 namespace nix {
 
-/**
- * We put a limit on primop arity because it lets us use a fixed size array on
- * the stack. 8 is already an impractical number of arguments. Use an attrset
- * argument for such overly complicated functions.
- */
-constexpr size_t maxPrimOpArity = 8;
 
 class Store;
 class EvalState;
@@ -77,16 +69,8 @@ struct PrimOp
      * Optional experimental for this to be gated on.
      */
     std::optional<ExperimentalFeature> experimentalFeature;
-
-    /**
-     * Validity check to be performed by functions that introduce primops,
-     * such as RegisterPrimOp() and Value::mkPrimOp().
-     */
-    void check();
 };
 
-std::ostream & operator<<(std::ostream & output, PrimOp & primOp);
-
 /**
  * Info about a constant
  */
@@ -119,6 +103,11 @@ struct Constant
 struct Env
 {
     Env * up;
+    /**
+     * Number of of levels up to next `with` environment
+     */
+    unsigned short prevWith:14;
+    enum { Plain = 0, HasWithExpr, HasWithAttrs } type:2;
     Value * values[0];
 };
 
@@ -130,7 +119,7 @@ std::unique_ptr<ValMap> mapStaticEnvBindings(const SymbolTable & st, const Stati
 void copyContext(const Value & v, NixStringContext & context);
 
 
-std::string printValue(EvalState & state, Value & v);
+std::string printValue(const EvalState & state, const Value & v);
 std::ostream & operator << (std::ostream & os, const ValueType t);
 
 
@@ -145,13 +134,52 @@ struct RegexCache;
 std::shared_ptr<RegexCache> makeRegexCache();
 
 struct DebugTrace {
-    std::shared_ptr<Pos> pos;
+    std::shared_ptr<AbstractPos> pos;
     const Expr & expr;
     const Env & env;
-    HintFmt hint;
+    hintformat hint;
     bool isError;
 };
 
+void debugError(Error * e, Env & env, Expr & expr);
+
+class ErrorBuilder
+{
+    private:
+        EvalState & state;
+        ErrorInfo info;
+
+        ErrorBuilder(EvalState & s, ErrorInfo && i): state(s), info(i) { }
+
+    public:
+        template<typename... Args>
+        [[nodiscard, gnu::noinline]]
+        static ErrorBuilder * create(EvalState & s, const Args & ... args)
+        {
+            return new ErrorBuilder(s, ErrorInfo { .msg = hintfmt(args...) });
+        }
+
+        [[nodiscard, gnu::noinline]]
+        ErrorBuilder & atPos(PosIdx pos);
+
+        [[nodiscard, gnu::noinline]]
+        ErrorBuilder & withTrace(PosIdx pos, const std::string_view text);
+
+        [[nodiscard, gnu::noinline]]
+        ErrorBuilder & withFrameTrace(PosIdx pos, const std::string_view text);
+
+        [[nodiscard, gnu::noinline]]
+        ErrorBuilder & withSuggestions(Suggestions & s);
+
+        [[nodiscard, gnu::noinline]]
+        ErrorBuilder & withFrame(const Env & e, const Expr & ex);
+
+        template<class ErrorType>
+        [[gnu::noinline, gnu::noreturn]]
+        void debugThrow();
+};
+
+
 class EvalState : public std::enable_shared_from_this<EvalState>
 {
 public:
@@ -169,8 +197,6 @@ public:
         sPrefix,
         sOutputSpecified;
 
-    const Expr::AstSymbols exprSymbols;
-
     /**
      * If set, force copying files to the Nix store even if they
      * already exist there.
@@ -185,11 +211,6 @@ public:
 
     Bindings emptyBindings;
 
-    /**
-     * Empty list constant.
-     */
-    Value vEmptyList;
-
     const SourcePath derivationInternal;
 
     /**
@@ -208,8 +229,9 @@ public:
     /**
      * Debugger
      */
-    ReplExitStatus (* debugRepl)(ref<EvalState> es, const ValMap & extraEnv);
+    void (* debugRepl)(ref<EvalState> es, const ValMap & extraEnv);
     bool debugStop;
+    bool debugQuit;
     int trylevel;
     std::list<DebugTrace> debugTraces;
     std::map<const Expr*, const std::shared_ptr<const StaticEnv>> exprEnvs;
@@ -224,11 +246,39 @@ public:
 
     void runDebugRepl(const Error * error, const Env & env, const Expr & expr);
 
-    template<class T, typename... Args>
+    template<class E>
+    [[gnu::noinline, gnu::noreturn]]
+    void debugThrowLastTrace(E && error)
+    {
+        debugThrow(error, nullptr, nullptr);
+    }
+
+    template<class E>
+    [[gnu::noinline, gnu::noreturn]]
+    void debugThrow(E && error, const Env * env, const Expr * expr)
+    {
+        if (debugRepl && ((env && expr) || !debugTraces.empty())) {
+            if (!env || !expr) {
+                const DebugTrace & last = debugTraces.front();
+                env = &last.env;
+                expr = &last.expr;
+            }
+            runDebugRepl(&error, *env, *expr);
+        }
+
+        throw std::move(error);
+    }
+
+    // This is dangerous, but gets in line with the idea that error creation and
+    // throwing should not allocate on the stack of hot functions.
+    // as long as errors are immediately thrown, it works.
+    ErrorBuilder * errorBuilder;
+
+    template<typename... Args>
     [[nodiscard, gnu::noinline]]
-    EvalErrorBuilder<T> & error(const Args & ... args) {
-        // `EvalErrorBuilder::debugThrow` performs the corresponding `delete`.
-        return *new EvalErrorBuilder<T>(*this, args...);
+    ErrorBuilder & error(const Args & ... args) {
+        errorBuilder = ErrorBuilder::create(*this, args...);
+        return *errorBuilder;
     }
 
 private:
@@ -405,7 +455,8 @@ public:
      */
     inline void forceValue(Value & v, const PosIdx pos);
 
-    void tryFixupBlackHolePos(Value & v, PosIdx pos);
+    template <typename Callable>
+    inline void forceValue(Value & v, Callable getPos);
 
     /**
      * Force a value, then recursively force list elements and
@@ -434,12 +485,10 @@ public:
     std::string_view forceString(Value & v, NixStringContext & context, const PosIdx pos, std::string_view errorCtx);
     std::string_view forceStringNoCtx(Value & v, const PosIdx pos, std::string_view errorCtx);
 
-    template<typename... Args>
     [[gnu::noinline]]
-    void addErrorTrace(Error & e, const Args & ... formatArgs) const;
-    template<typename... Args>
+    void addErrorTrace(Error & e, const char * s, const std::string & s2) const;
     [[gnu::noinline]]
-    void addErrorTrace(Error & e, const PosIdx pos, const Args & ... formatArgs) const;
+    void addErrorTrace(Error & e, const PosIdx pos, const char * s, const std::string & s2, bool frame = false) const;
 
 public:
     /**
@@ -569,11 +618,6 @@ private:
         const SourcePath & basePath,
         std::shared_ptr<StaticEnv> & staticEnv);
 
-    /**
-     * Current Nix call stack depth, used with `max-call-depth` setting to throw stack overflow hopefully before we run out of system stack.
-     */
-    size_t callDepth = 0;
-
 public:
 
     /**
@@ -665,25 +709,9 @@ public:
     void concatLists(Value & v, size_t nrLists, Value * * lists, const PosIdx pos, std::string_view errorCtx);
 
     /**
-     * Print statistics, if enabled.
-     *
-     * Performs a full memory GC before printing the statistics, so that the
-     * GC statistics are more accurate.
+     * Print statistics.
      */
-    void maybePrintStats();
-
-    /**
-     * Print statistics, unconditionally, cheaply, without performing a GC first.
-     */
-    void printStatistics();
-
-    /**
-     * Perform a full memory garbage collection - not incremental.
-     *
-     * @return true if Nix was built with GC and a GC was performed, false if not.
-     *              The return value is currently not thread safe - just the return value.
-     */
-    bool fullGC();
+    void printStats();
 
     /**
      * Realise the given context, and return a mapping from the placeholders
@@ -755,6 +783,7 @@ struct DebugTraceStacker {
     DebugTraceStacker(EvalState & evalState, DebugTrace t);
     ~DebugTraceStacker()
     {
+        // assert(evalState.debugTraces.front() == trace);
         evalState.debugTraces.pop_front();
     }
     EvalState & evalState;
@@ -775,8 +804,23 @@ std::string showType(const Value & v);
  */
 SourcePath resolveExprPath(SourcePath path);
 
+struct InvalidPathError : EvalError
+{
+    Path path;
+    InvalidPathError(const Path & path);
+#ifdef EXCEPTION_NEEDS_THROW_SPEC
+    ~InvalidPathError() throw () { };
+#endif
+};
+
 static const std::string corepkgsPrefix{"/__corepkgs__/"};
 
+template<class ErrorType>
+void ErrorBuilder::debugThrow()
+{
+    // NOTE: We always use the -LastTrace version as we push the new trace in withFrame()
+    state.debugThrowLastTrace(ErrorType(info));
+}
 
 }
 

src/libexpr/flake/flake.cc

@@ -140,15 +140,15 @@ static FlakeInput parseFlakeInput(EvalState & state,
                         attrs.emplace(state.symbols[attr.name], (long unsigned int)attr.value->integer);
                         break;
                     default:
-                        state.error<TypeError>("flake input attribute '%s' is %s while a string, Boolean, or integer is expected",
-                            state.symbols[attr.name], showType(*attr.value)).debugThrow();
+                        throw TypeError("flake input attribute '%s' is %s while a string, Boolean, or integer is expected",
+                            state.symbols[attr.name], showType(*attr.value));
                 }
                 #pragma GCC diagnostic pop
             }
         } catch (Error & e) {
             e.addTrace(
                 state.positions[attr.pos],
-                HintFmt("while evaluating flake attribute '%s'", state.symbols[attr.name]));
+                hintfmt("while evaluating flake attribute '%s'", state.symbols[attr.name]));
             throw;
         }
     }
@@ -157,7 +157,7 @@ static FlakeInput parseFlakeInput(EvalState & state,
         try {
             input.ref = FlakeRef::fromAttrs(attrs);
         } catch (Error & e) {
-            e.addTrace(state.positions[pos], HintFmt("while evaluating flake input"));
+            e.addTrace(state.positions[pos], hintfmt("while evaluating flake input"));
             throw;
         }
     else {
@@ -205,16 +205,8 @@ static Flake getFlake(
     auto [sourceInfo, resolvedRef, lockedRef] = fetchOrSubstituteTree(
         state, originalRef, allowLookup, flakeCache);
 
-    // We need to guard against symlink attacks, but before we start doing
-    // filesystem operations we should make sure there's a flake.nix in the
-    // first place.
-    auto unsafeFlakeDir = sourceInfo.actualPath + "/" + lockedRef.subdir;
-    auto unsafeFlakeFile = unsafeFlakeDir + "/flake.nix";
-    if (!pathExists(unsafeFlakeFile))
-        throw Error("source tree referenced by '%s' does not contain a '%s/flake.nix' file", lockedRef, lockedRef.subdir);
-
     // Guard against symlink attacks.
-    auto flakeDir = canonPath(unsafeFlakeDir, true);
+    auto flakeDir = canonPath(sourceInfo.actualPath + "/" + lockedRef.subdir, true);
     auto flakeFile = canonPath(flakeDir + "/flake.nix", true);
     if (!isInDir(flakeFile, sourceInfo.actualPath))
         throw Error("'flake.nix' file of flake '%s' escapes from '%s'",
@@ -227,6 +219,9 @@ static Flake getFlake(
         .sourceInfo = std::make_shared<fetchers::Tree>(std::move(sourceInfo))
     };
 
+    if (!pathExists(flakeFile))
+        throw Error("source tree referenced by '%s' does not contain a '%s/flake.nix' file", lockedRef, lockedRef.subdir);
+
     Value vInfo;
     state.evalFile(CanonPath(flakeFile), vInfo, true); // FIXME: symlink attack
 
@@ -288,15 +283,15 @@ static Flake getFlake(
                 std::vector<std::string> ss;
                 for (auto elem : setting.value->listItems()) {
                     if (elem->type() != nString)
-                        state.error<TypeError>("list element in flake configuration setting '%s' is %s while a string is expected",
-                            state.symbols[setting.name], showType(*setting.value)).debugThrow();
+                        throw TypeError("list element in flake configuration setting '%s' is %s while a string is expected",
+                            state.symbols[setting.name], showType(*setting.value));
                     ss.emplace_back(state.forceStringNoCtx(*elem, setting.pos, ""));
                 }
                 flake.config.settings.emplace(state.symbols[setting.name], ss);
             }
             else
-                state.error<TypeError>("flake configuration setting '%s' is %s",
-                    state.symbols[setting.name], showType(*setting.value)).debugThrow();
+                throw TypeError("flake configuration setting '%s' is %s",
+                    state.symbols[setting.name], showType(*setting.value));
         }
     }
 
@@ -857,11 +852,11 @@ static void prim_flakeRefToString(
             attrs.emplace(state.symbols[attr.name],
                           std::string(attr.value->str()));
         } else {
-            state.error<EvalError>(
+            state.error(
                 "flake reference attribute sets may only contain integers, Booleans, "
                 "and strings, but attribute '%s' is %s",
                 state.symbols[attr.name],
-                showType(*attr.value)).debugThrow();
+                showType(*attr.value)).debugThrow<EvalError>();
         }
     }
     auto flakeRef = FlakeRef::fromAttrs(attrs);

src/libexpr/flake/lockfile.cc

@@ -89,7 +89,7 @@ LockFile::LockFile(const nlohmann::json & json, const Path & path)
                 std::string inputKey = i.value();
                 auto k = nodeMap.find(inputKey);
                 if (k == nodeMap.end()) {
-                    auto & nodes = json["nodes"];
+                    auto nodes = json["nodes"];
                     auto jsonNode2 = nodes.find(inputKey);
                     if (jsonNode2 == nodes.end())
                         throw Error("lock file references missing node '%s'", inputKey);

src/libexpr/gc-small-vector.hh

@@ -1,42 +0,0 @@
-#pragma once
-
-#include <boost/container/small_vector.hpp>
-
-#if HAVE_BOEHMGC
-
-#include <gc/gc.h>
-#include <gc/gc_cpp.h>
-#include <gc/gc_allocator.h>
-
-#endif
-
-namespace nix {
-
-struct Value;
-
-/**
- * A GC compatible vector that may used a reserved portion of `nItems` on the stack instead of allocating on the heap.
- */
-#if HAVE_BOEHMGC
-template <typename T, size_t nItems>
-using SmallVector = boost::container::small_vector<T, nItems, traceable_allocator<T>>;
-#else
-template <typename T, size_t nItems>
-using SmallVector = boost::container::small_vector<T, nItems>;
-#endif
-
-/**
- * A vector of value pointers. See `SmallVector`.
- */
-template <size_t nItems>
-using SmallValueVector = SmallVector<Value *, nItems>;
-
-/**
- * A vector of values that must not be referenced after the vector is destroyed.
- *
- * See also `SmallValueVector`.
- */
-template <size_t nItems>
-using SmallTemporaryValueVector = SmallVector<Value, nItems>;
-
-}

src/libexpr/get-drvs.cc

@@ -50,7 +50,7 @@ std::string DrvInfo::queryName() const
 {
     if (name == "" && attrs) {
         auto i = attrs->find(state->sName);
-        if (i == attrs->end()) state->error<TypeError>("derivation name missing").debugThrow();
+        if (i == attrs->end()) throw TypeError("derivation name missing");
         name = state->forceStringNoCtx(*i->value, noPos, "while evaluating the 'name' attribute of a derivation");
     }
     return name;
@@ -199,7 +199,7 @@ StringSet DrvInfo::queryMetaNames()
 
 bool DrvInfo::checkMeta(Value & v)
 {
-    state->forceValue(v, v.determinePos(noPos));
+    state->forceValue(v, [&]() { return v.determinePos(noPos); });
     if (v.type() == nList) {
         for (auto elem : v.listItems())
             if (!checkMeta(*elem)) return false;
@@ -296,16 +296,22 @@ void DrvInfo::setMeta(const std::string & name, Value * v)
 typedef std::set<Bindings *> Done;
 
 
-/* The result boolean indicates whether it makes sense
+/* Evaluate value `v'.  If it evaluates to a set of type `derivation',
+   then put information about it in `drvs' (unless it's already in `done').
+   The result boolean indicates whether it makes sense
    for the caller to recursively search for derivations in `v'. */
 static bool getDerivation(EvalState & state, Value & v,
-    const std::string & attrPath, DrvInfos & drvs,
+    const std::string & attrPath, DrvInfos & drvs, Done & done,
     bool ignoreAssertionFailures)
 {
     try {
-        state.forceValue(v, v.determinePos(noPos));
+        state.forceValue(v, [&]() { return v.determinePos(noPos); });
         if (!state.isDerivation(v)) return true;
 
+        /* Remove spurious duplicates (e.g., a set like `rec { x =
+           derivation {...}; y = x;}'. */
+        if (!done.insert(v.attrs).second) return false;
+
         DrvInfo drv(state, attrPath, v.attrs);
 
         drv.queryName();
@@ -324,8 +330,9 @@ static bool getDerivation(EvalState & state, Value & v,
 std::optional<DrvInfo> getDerivation(EvalState & state, Value & v,
     bool ignoreAssertionFailures)
 {
+    Done done;
     DrvInfos drvs;
-    getDerivation(state, v, "", drvs, ignoreAssertionFailures);
+    getDerivation(state, v, "", drvs, done, ignoreAssertionFailures);
     if (drvs.size() != 1) return {};
     return std::move(drvs.front());
 }
@@ -340,9 +347,6 @@ static std::string addToPath(const std::string & s1, const std::string & s2)
 static std::regex attrRegex("[A-Za-z_][A-Za-z0-9-_+]*");
 
 
-/* Evaluate value `v'.  If it evaluates to a set of type `derivation',
-   then put information about it in `drvs'. If it evaluates to a different
-   kind of set recurse (unless it's already in `done'). */
 static void getDerivations(EvalState & state, Value & vIn,
     const std::string & pathPrefix, Bindings & autoArgs,
     DrvInfos & drvs, Done & done,
@@ -352,14 +356,10 @@ static void getDerivations(EvalState & state, Value & vIn,
     state.autoCallFunction(autoArgs, vIn, v);
 
     /* Process the expression. */
-    if (!getDerivation(state, v, pathPrefix, drvs, ignoreAssertionFailures)) ;
+    if (!getDerivation(state, v, pathPrefix, drvs, done, ignoreAssertionFailures)) ;
 
     else if (v.type() == nAttrs) {
 
-        /* Dont consider sets we've already seen, e.g. y in
-           `rec { x.d = derivation {...}; y = x; }`. */
-        if (!done.insert(v.attrs).second) return;
-
         /* !!! undocumented hackery to support combining channels in
            nix-env.cc. */
         bool combineChannels = v.attrs->find(state.symbols.create("_combineChannels")) != v.attrs->end();
@@ -376,7 +376,7 @@ static void getDerivations(EvalState & state, Value & vIn,
             std::string pathPrefix2 = addToPath(pathPrefix, state.symbols[i->name]);
             if (combineChannels)
                 getDerivations(state, *i->value, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
-            else if (getDerivation(state, *i->value, pathPrefix2, drvs, ignoreAssertionFailures)) {
+            else if (getDerivation(state, *i->value, pathPrefix2, drvs, done, ignoreAssertionFailures)) {
                 /* If the value of this attribute is itself a set,
                    should we recurse into it?  => Only if it has a
                    `recurseForDerivations = true' attribute. */
@@ -390,17 +390,14 @@ static void getDerivations(EvalState & state, Value & vIn,
     }
 
     else if (v.type() == nList) {
-        // NOTE we can't really deduplicate here because small lists don't have stable addresses
-        // and can cause spurious duplicate detections due to v being on the stack.
         for (auto [n, elem] : enumerate(v.listItems())) {
             std::string pathPrefix2 = addToPath(pathPrefix, fmt("%d", n));
-            if (getDerivation(state, *elem, pathPrefix2, drvs, ignoreAssertionFailures))
+            if (getDerivation(state, *elem, pathPrefix2, drvs, done, ignoreAssertionFailures))
                 getDerivations(state, *elem, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
         }
     }
 
-    else
-        state.error<TypeError>("expression does not evaluate to a derivation (or a set or list of those)").debugThrow();
+    else throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
 }
 
 

src/libexpr/json-to-value.cc

@@ -1,6 +1,4 @@
 #include "json-to-value.hh"
-#include "value.hh"
-#include "eval.hh"
 
 #include <variant>
 #include <nlohmann/json.hpp>
@@ -161,7 +159,7 @@ public:
     }
 
     bool parse_error(std::size_t, const std::string&, const nlohmann::detail::exception& ex) {
-        throw JSONParseError("%s", ex.what());
+        throw JSONParseError(ex.what());
     }
 };
 

src/libexpr/json-to-value.hh

@@ -1,16 +1,13 @@
 #pragma once
 ///@file
 
-#include "error.hh"
+#include "eval.hh"
 
 #include <string>
 
 namespace nix {
 
-class EvalState;
-struct Value;
-
-MakeError(JSONParseError, Error);
+MakeError(JSONParseError, EvalError);
 
 void parseJSON(EvalState & state, const std::string_view & s, Value & v);
 

src/libexpr/lexer.l

@@ -1,5 +1,4 @@
 %option reentrant bison-bridge bison-locations
-%option align
 %option noyywrap
 %option never-interactive
 %option stack
@@ -20,12 +19,6 @@
 #pragma clang diagnostic ignored "-Wunneeded-internal-declaration"
 #endif
 
-// yacc generates code that uses unannotated fallthrough.
-#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
-#ifdef __clang__
-#pragma clang diagnostic ignored "-Wimplicit-fallthrough"
-#endif
-
 #include <boost/lexical_cast.hpp>
 
 #include "nixexpr.hh"
@@ -35,7 +28,15 @@ using namespace nix;
 
 namespace nix {
 
-#define CUR_POS state->at(*yylloc)
+static inline PosIdx makeCurPos(const YYLTYPE & loc, ParseData * data)
+{
+    return data->state.positions.add(data->origin, loc.first_line, loc.first_column);
+}
+
+#define CUR_POS makeCurPos(*yylloc, data)
+
+// backup to recover from yyless(0)
+thread_local YYLTYPE prev_yylloc;
 
 static void initLoc(YYLTYPE * loc)
 {
@@ -45,7 +46,7 @@ static void initLoc(YYLTYPE * loc)
 
 static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
 {
-    loc->stash();
+    prev_yylloc = *loc;
 
     loc->first_line = loc->last_line;
     loc->first_column = loc->last_column;
@@ -152,9 +153,9 @@ or          { return OR_KW; }
               try {
                   yylval->n = boost::lexical_cast<int64_t>(yytext);
               } catch (const boost::bad_lexical_cast &) {
-                  throw ParseError(ErrorInfo{
-                      .msg = HintFmt("invalid integer '%1%'", yytext),
-                      .pos = state->positions[CUR_POS],
+                  throw ParseError({
+                      .msg = hintfmt("invalid integer '%1%'", yytext),
+                      .errPos = data->state.positions[CUR_POS],
                   });
               }
               return INT;
@@ -162,9 +163,9 @@ or          { return OR_KW; }
 {FLOAT}     { errno = 0;
               yylval->nf = strtod(yytext, 0);
               if (errno != 0)
-                  throw ParseError(ErrorInfo{
-                      .msg = HintFmt("invalid float '%1%'", yytext),
-                      .pos = state->positions[CUR_POS],
+                  throw ParseError({
+                      .msg = hintfmt("invalid float '%1%'", yytext),
+                      .errPos = data->state.positions[CUR_POS],
                   });
               return FLOAT;
             }
@@ -187,7 +188,7 @@ or          { return OR_KW; }
                 /* It is impossible to match strings ending with '$' with one
                    regex because trailing contexts are only valid at the end
                    of a rule. (A sane but undocumented limitation.) */
-                yylval->str = unescapeStr(state->symbols, yytext, yyleng);
+                yylval->str = unescapeStr(data->symbols, yytext, yyleng);
                 return STR;
               }
 <STRING>\$\{  { PUSH_STATE(DEFAULT); return DOLLAR_CURLY; }
@@ -215,7 +216,7 @@ or          { return OR_KW; }
                    return IND_STR;
                  }
 <IND_STRING>\'\'\\{ANY} {
-                   yylval->str = unescapeStr(state->symbols, yytext + 2, yyleng - 2);
+                   yylval->str = unescapeStr(data->symbols, yytext + 2, yyleng - 2);
                    return IND_STR;
                  }
 <IND_STRING>\$\{ { PUSH_STATE(DEFAULT); return DOLLAR_CURLY; }
@@ -229,7 +230,7 @@ or          { return OR_KW; }
 {HPATH_START}\$\{ {
   PUSH_STATE(PATH_START);
   yyless(0);
-  yylloc->unstash();
+  *yylloc = prev_yylloc;
 }
 
 <PATH_START>{PATH_SEG} {
@@ -285,15 +286,15 @@ or          { return OR_KW; }
      context (it may be ')', ';', or something of that sort) */
   POP_STATE();
   yyless(0);
-  yylloc->unstash();
+  *yylloc = prev_yylloc;
   return PATH_END;
 }
 
 <INPATH_SLASH>{ANY} |
 <INPATH_SLASH><<EOF>> {
-  throw ParseError(ErrorInfo{
-      .msg = HintFmt("path has a trailing slash"),
-      .pos = state->positions[CUR_POS],
+  throw ParseError({
+      .msg = hintfmt("path has a trailing slash"),
+      .errPos = data->state.positions[CUR_POS],
   });
 }
 

src/libexpr/local.mk

@@ -36,15 +36,15 @@ $(d)/lexer-tab.cc $(d)/lexer-tab.hh: $(d)/lexer.l
 
 clean-files += $(d)/parser-tab.cc $(d)/parser-tab.hh $(d)/lexer-tab.cc $(d)/lexer-tab.hh
 
-$(eval $(call install-file-in, $(buildprefix)$(d)/nix-expr.pc, $(libdir)/pkgconfig, 0644))
+$(eval $(call install-file-in, $(d)/nix-expr.pc, $(libdir)/pkgconfig, 0644))
 
 $(foreach i, $(wildcard src/libexpr/value/*.hh), \
   $(eval $(call install-file-in, $(i), $(includedir)/nix/value, 0644)))
 $(foreach i, $(wildcard src/libexpr/flake/*.hh), \
   $(eval $(call install-file-in, $(i), $(includedir)/nix/flake, 0644)))
 
-$(d)/primops.cc: $(d)/imported-drv-to-derivation.nix.gen.hh
+$(d)/primops.cc: $(d)/imported-drv-to-derivation.nix.gen.hh $(d)/primops/derivation.nix.gen.hh $(d)/fetchurl.nix.gen.hh
 
-$(d)/eval.cc: $(d)/primops/derivation.nix.gen.hh $(d)/fetchurl.nix.gen.hh $(d)/flake/call-flake.nix.gen.hh
+$(d)/flake/flake.cc: $(d)/flake/call-flake.nix.gen.hh
 
-$(buildprefix)src/libexpr/primops/fromTOML.o:	ERROR_SWITCH_ENUM =
+src/libexpr/primops/fromTOML.o:	ERROR_SWITCH_ENUM =

src/libexpr/nixexpr.cc

@@ -9,7 +9,57 @@
 
 namespace nix {
 
-ExprBlackHole eBlackHole;
+struct PosAdapter : AbstractPos
+{
+    Pos::Origin origin;
+
+    PosAdapter(Pos::Origin origin)
+        : origin(std::move(origin))
+    {
+    }
+
+    std::optional<std::string> getSource() const override
+    {
+        return std::visit(overloaded {
+            [](const Pos::none_tag &) -> std::optional<std::string> {
+                return std::nullopt;
+            },
+            [](const Pos::Stdin & s) -> std::optional<std::string> {
+                // Get rid of the null terminators added by the parser.
+                return std::string(s.source->c_str());
+            },
+            [](const Pos::String & s) -> std::optional<std::string> {
+                // Get rid of the null terminators added by the parser.
+                return std::string(s.source->c_str());
+            },
+            [](const SourcePath & path) -> std::optional<std::string> {
+                try {
+                    return path.readFile();
+                } catch (Error &) {
+                    return std::nullopt;
+                }
+            }
+        }, origin);
+    }
+
+    void print(std::ostream & out) const override
+    {
+        std::visit(overloaded {
+            [&](const Pos::none_tag &) { out << "«none»"; },
+            [&](const Pos::Stdin &) { out << "«stdin»"; },
+            [&](const Pos::String & s) { out << "«string»"; },
+            [&](const SourcePath & path) { out << path; }
+        }, origin);
+    }
+};
+
+Pos::operator std::shared_ptr<AbstractPos>() const
+{
+    auto pos = std::make_shared<PosAdapter>(origin);
+    pos->line = line;
+    pos->column = column;
+    return pos;
+}
 
 // FIXME: remove, because *symbols* are abstract and do not have a single
 //        textual representation; see printIdentifier()
@@ -68,8 +118,10 @@ void ExprOpHasAttr::show(const SymbolTable & symbols, std::ostream & str) const
     str << ") ? " << showAttrPath(symbols, attrPath) << ")";
 }
 
-void ExprAttrs::showBindings(const SymbolTable & symbols, std::ostream & str) const
+void ExprAttrs::show(const SymbolTable & symbols, std::ostream & str) const
 {
+    if (recursive) str << "rec ";
+    str << "{ ";
     typedef const decltype(attrs)::value_type * Attr;
     std::vector<Attr> sorted;
     for (auto & i : attrs) sorted.push_back(&i);
@@ -77,37 +129,10 @@ void ExprAttrs::showBindings(const SymbolTable & symbols, std::ostream & str) co
         std::string_view sa = symbols[a->first], sb = symbols[b->first];
         return sa < sb;
     });
-    std::vector<Symbol> inherits;
-    std::map<ExprInheritFrom *, std::vector<Symbol>> inheritsFrom;
     for (auto & i : sorted) {
-        switch (i->second.kind) {
-        case AttrDef::Kind::Plain:
-            break;
-        case AttrDef::Kind::Inherited:
-            inherits.push_back(i->first);
-            break;
-        case AttrDef::Kind::InheritedFrom: {
-            auto & select = dynamic_cast<ExprSelect &>(*i->second.e);
-            auto & from = dynamic_cast<ExprInheritFrom &>(*select.e);
-            inheritsFrom[&from].push_back(i->first);
-            break;
-        }
-        }
-    }
-    if (!inherits.empty()) {
-        str << "inherit";
-        for (auto sym : inherits) str << " " << symbols[sym];
-        str << "; ";
-    }
-    for (const auto & [from, syms] : inheritsFrom) {
-        str << "inherit (";
-        (*inheritFromExprs)[from->displ]->show(symbols, str);
-        str << ")";
-        for (auto sym : syms) str << " " << symbols[sym];
-        str << "; ";
-    }
-    for (auto & i : sorted) {
-        if (i->second.kind == AttrDef::Kind::Plain) {
+        if (i->second.inherited)
+            str << "inherit " << symbols[i->first] << " " << "; ";
+        else {
             str << symbols[i->first] << " = ";
             i->second.e->show(symbols, str);
             str << "; ";
@@ -120,13 +145,6 @@ void ExprAttrs::showBindings(const SymbolTable & symbols, std::ostream & str) co
         i.valueExpr->show(symbols, str);
         str << "; ";
     }
-}
-
-void ExprAttrs::show(const SymbolTable & symbols, std::ostream & str) const
-{
-    if (recursive) str << "rec ";
-    str << "{ ";
-    showBindings(symbols, str);
     str << "}";
 }
 
@@ -182,7 +200,15 @@ void ExprCall::show(const SymbolTable & symbols, std::ostream & str) const
 void ExprLet::show(const SymbolTable & symbols, std::ostream & str) const
 {
     str << "(let ";
-    attrs->showBindings(symbols, str);
+    for (auto & i : attrs->attrs)
+        if (i.second.inherited) {
+            str << "inherit " << symbols[i.first] << "; ";
+        }
+        else {
+            str << symbols[i.first] << " = ";
+            i.second.e->show(symbols, str);
+            str << "; ";
+        }
     str << "in ";
     body->show(symbols, str);
     str << ")";
@@ -240,6 +266,17 @@ void ExprPos::show(const SymbolTable & symbols, std::ostream & str) const
 }
 
 
+std::ostream & operator << (std::ostream & str, const Pos & pos)
+{
+    if (auto pos2 = (std::shared_ptr<AbstractPos>) pos) {
+        str << *pos2;
+    } else
+        str << "undefined position";
+
+    return str;
+}
+
+
 std::string showAttrPath(const SymbolTable & symbols, const AttrPath & attrPath)
 {
     std::ostringstream out;
@@ -294,8 +331,6 @@ void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
     if (es.debugRepl)
         es.exprEnvs.insert(std::make_pair(this, env));
 
-    fromWith = nullptr;
-
     /* Check whether the variable appears in the environment.  If so,
        set its level and displacement. */
     const StaticEnv * curEnv;
@@ -307,6 +342,7 @@ void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
         } else {
             auto i = curEnv->find(name);
             if (i != curEnv->vars.end()) {
+                fromWith = false;
                 this->level = level;
                 displ = i->second;
                 return;
@@ -318,21 +354,14 @@ void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
        enclosing `with'.  If there is no `with', then we can issue an
        "undefined variable" error now. */
     if (withLevel == -1)
-        es.error<UndefinedVarError>(
-            "undefined variable '%1%'",
-            es.symbols[name]
-        ).atPos(pos).debugThrow();
-    for (auto * e = env.get(); e && !fromWith; e = e->up)
-        fromWith = e->isWith;
+        throw UndefinedVarError({
+            .msg = hintfmt("undefined variable '%1%'", es.symbols[name]),
+            .errPos = es.positions[pos]
+        });
+    fromWith = true;
     this->level = withLevel;
 }
 
-void ExprInheritFrom::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
-{
-    if (es.debugRepl)
-        es.exprEnvs.insert(std::make_pair(this, env));
-}
-
 void ExprSelect::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
 {
     if (es.debugRepl)
@@ -356,47 +385,22 @@ void ExprOpHasAttr::bindVars(EvalState & es, const std::shared_ptr<const StaticE
             i.expr->bindVars(es, env);
 }
 
-std::shared_ptr<const StaticEnv> ExprAttrs::bindInheritSources(
-    EvalState & es, const std::shared_ptr<const StaticEnv> & env)
-{
-    if (!inheritFromExprs)
-        return nullptr;
-
-    // the inherit (from) source values are inserted into an env of its own, which
-    // does not introduce any variable names.
-    // analysis must see an empty env, or an env that contains only entries with
-    // otherwise unused names to not interfere with regular names. the parser
-    // has already filled all exprs that access this env with appropriate level
-    // and displacement, and nothing else is allowed to access it. ideally we'd
-    // not even *have* an expr that grabs anything from this env since it's fully
-    // invisible, but the evaluator does not allow for this yet.
-    auto inner = std::make_shared<StaticEnv>(nullptr, env.get(), 0);
-    for (auto from : *inheritFromExprs)
-        from->bindVars(es, env);
-
-    return inner;
-}
-
 void ExprAttrs::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
 {
     if (es.debugRepl)
         es.exprEnvs.insert(std::make_pair(this, env));
 
     if (recursive) {
-        auto newEnv = [&] () -> std::shared_ptr<const StaticEnv> {
-            auto newEnv = std::make_shared<StaticEnv>(nullptr, env.get(), attrs.size());
+        auto newEnv = std::make_shared<StaticEnv>(false, env.get(), recursive ? attrs.size() : 0);
 
-            Displacement displ = 0;
-            for (auto & i : attrs)
-                newEnv->vars.emplace_back(i.first, i.second.displ = displ++);
-            return newEnv;
-        }();
+        Displacement displ = 0;
+        for (auto & i : attrs)
+            newEnv->vars.emplace_back(i.first, i.second.displ = displ++);
 
         // No need to sort newEnv since attrs is in sorted order.
 
-        auto inheritFromEnv = bindInheritSources(es, newEnv);
         for (auto & i : attrs)
-            i.second.e->bindVars(es, i.second.chooseByKind(newEnv, env, inheritFromEnv));
+            i.second.e->bindVars(es, i.second.inherited ? env : newEnv);
 
         for (auto & i : dynamicAttrs) {
             i.nameExpr->bindVars(es, newEnv);
@@ -404,10 +408,8 @@ void ExprAttrs::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv>
         }
     }
     else {
-        auto inheritFromEnv = bindInheritSources(es, env);
-
         for (auto & i : attrs)
-            i.second.e->bindVars(es, i.second.chooseByKind(env, env, inheritFromEnv));
+            i.second.e->bindVars(es, env);
 
         for (auto & i : dynamicAttrs) {
             i.nameExpr->bindVars(es, env);
@@ -431,7 +433,7 @@ void ExprLambda::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv>
         es.exprEnvs.insert(std::make_pair(this, env));
 
     auto newEnv = std::make_shared<StaticEnv>(
-        nullptr, env.get(),
+        false, env.get(),
         (hasFormals() ? formals->formals.size() : 0) +
         (!arg ? 0 : 1));
 
@@ -464,23 +466,19 @@ void ExprCall::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
 
 void ExprLet::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
 {
-    auto newEnv = [&] () -> std::shared_ptr<const StaticEnv> {
-        auto newEnv = std::make_shared<StaticEnv>(nullptr, env.get(), attrs->attrs.size());
+    if (es.debugRepl)
+        es.exprEnvs.insert(std::make_pair(this, env));
 
-        Displacement displ = 0;
-        for (auto & i : attrs->attrs)
-            newEnv->vars.emplace_back(i.first, i.second.displ = displ++);
-        return newEnv;
-    }();
+    auto newEnv = std::make_shared<StaticEnv>(false, env.get(), attrs->attrs.size());
+
+    Displacement displ = 0;
+    for (auto & i : attrs->attrs)
+        newEnv->vars.emplace_back(i.first, i.second.displ = displ++);
 
     // No need to sort newEnv since attrs->attrs is in sorted order.
 
-    auto inheritFromEnv = attrs->bindInheritSources(es, newEnv);
     for (auto & i : attrs->attrs)
-        i.second.e->bindVars(es, i.second.chooseByKind(newEnv, env, inheritFromEnv));
-
-    if (es.debugRepl)
-        es.exprEnvs.insert(std::make_pair(this, newEnv));
+        i.second.e->bindVars(es, i.second.inherited ? env : newEnv);
 
     body->bindVars(es, newEnv);
 }
@@ -490,10 +488,6 @@ void ExprWith::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
     if (es.debugRepl)
         es.exprEnvs.insert(std::make_pair(this, env));
 
-    parentWith = nullptr;
-    for (auto * e = env.get(); e && !parentWith; e = e->up)
-        parentWith = e->isWith;
-
     /* Does this `with' have an enclosing `with'?  If so, record its
        level so that `lookupVar' can look up variables in the previous
        `with' if this one doesn't contain the desired attribute. */
@@ -506,8 +500,11 @@ void ExprWith::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> &
             break;
         }
 
+    if (es.debugRepl)
+        es.exprEnvs.insert(std::make_pair(this, env));
+
     attrs->bindVars(es, env);
-    auto newEnv = std::make_shared<StaticEnv>(this, env.get());
+    auto newEnv = std::make_shared<StaticEnv>(true, env.get());
     body->bindVars(es, newEnv);
 }
 

src/libexpr/nixexpr.hh

@@ -8,18 +8,130 @@
 #include "symbol-table.hh"
 #include "error.hh"
 #include "chunked-vector.hh"
-#include "position.hh"
-#include "eval-error.hh"
-#include "pos-idx.hh"
-#include "pos-table.hh"
 
 namespace nix {
 
 
+MakeError(EvalError, Error);
+MakeError(ParseError, Error);
+MakeError(AssertionError, EvalError);
+MakeError(ThrownError, AssertionError);
+MakeError(Abort, EvalError);
+MakeError(TypeError, EvalError);
+MakeError(UndefinedVarError, Error);
+MakeError(MissingArgumentError, EvalError);
+MakeError(RestrictedPathError, Error);
+
+/**
+ * Position objects.
+ */
+struct Pos
+{
+    uint32_t line;
+    uint32_t column;
+
+    struct none_tag { };
+    struct Stdin { ref<std::string> source; };
+    struct String { ref<std::string> source; };
+
+    typedef std::variant<none_tag, Stdin, String, SourcePath> Origin;
+
+    Origin origin;
+
+    explicit operator bool() const { return line > 0; }
+
+    operator std::shared_ptr<AbstractPos>() const;
+};
+
+class PosIdx {
+    friend class PosTable;
+
+private:
+    uint32_t id;
+
+    explicit PosIdx(uint32_t id): id(id) {}
+
+public:
+    PosIdx() : id(0) {}
+
+    explicit operator bool() const { return id > 0; }
+
+    bool operator <(const PosIdx other) const { return id < other.id; }
+
+    bool operator ==(const PosIdx other) const { return id == other.id; }
+
+    bool operator !=(const PosIdx other) const { return id != other.id; }
+};
+
+class PosTable
+{
+public:
+    class Origin {
+        friend PosTable;
+    private:
+        // must always be invalid by default, add() replaces this with the actual value.
+        // subsequent add() calls use this index as a token to quickly check whether the
+        // current origins.back() can be reused or not.
+        mutable uint32_t idx = std::numeric_limits<uint32_t>::max();
+
+        // Used for searching in PosTable::[].
+        explicit Origin(uint32_t idx): idx(idx), origin{Pos::none_tag()} {}
+
+    public:
+        const Pos::Origin origin;
+
+        Origin(Pos::Origin origin): origin(origin) {}
+    };
+
+    struct Offset {
+        uint32_t line, column;
+    };
+
+private:
+    std::vector<Origin> origins;
+    ChunkedVector<Offset, 8192> offsets;
+
+public:
+    PosTable(): offsets(1024)
+    {
+        origins.reserve(1024);
+    }
+
+    PosIdx add(const Origin & origin, uint32_t line, uint32_t column)
+    {
+        const auto idx = offsets.add({line, column}).second;
+        if (origins.empty() || origins.back().idx != origin.idx) {
+            origin.idx = idx;
+            origins.push_back(origin);
+        }
+        return PosIdx(idx + 1);
+    }
+
+    Pos operator[](PosIdx p) const
+    {
+        if (p.id == 0 || p.id > offsets.size())
+            return {};
+        const auto idx = p.id - 1;
+        /* we want the last key <= idx, so we'll take prev(first key > idx).
+           this is guaranteed to never rewind origin.begin because the first
+           key is always 0. */
+        const auto pastOrigin = std::upper_bound(
+            origins.begin(), origins.end(), Origin(idx),
+            [] (const auto & a, const auto & b) { return a.idx < b.idx; });
+        const auto origin = *std::prev(pastOrigin);
+        const auto offset = offsets[idx];
+        return {offset.line, offset.column, origin.origin};
+    }
+};
+
+inline PosIdx noPos = {};
+
+std::ostream & operator << (std::ostream & str, const Pos & pos);
+
+
 struct Env;
 struct Value;
 class EvalState;
-struct ExprWith;
 struct StaticEnv;
 
 
@@ -43,11 +155,6 @@ std::string showAttrPath(const SymbolTable & symbols, const AttrPath & attrPath)
 
 struct Expr
 {
-    struct AstSymbols {
-        Symbol sub, lessThan, mul, div, or_, findFile, nixPath, body;
-    };
-
-
     virtual ~Expr() { };
     virtual void show(const SymbolTable & symbols, std::ostream & str) const;
     virtual void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);
@@ -107,11 +214,8 @@ struct ExprVar : Expr
     Symbol name;
 
     /* Whether the variable comes from an environment (e.g. a rec, let
-       or function argument) or from a "with".
-
-       `nullptr`: Not from a `with`.
-       Valid pointer: the nearest, innermost `with` expression to query first. */
-    ExprWith * fromWith;
+       or function argument) or from a "with". */
+    bool fromWith;
 
     /* In the former case, the value is obtained by going `level`
        levels up from the current environment and getting the
@@ -129,29 +233,12 @@ struct ExprVar : Expr
     COMMON_METHODS
 };
 
-/**
- * A pseudo-expression for the purpose of evaluating the `from` expression in `inherit (from)` syntax.
- * Unlike normal variable references, the displacement is set during parsing, and always refers to
- * `ExprAttrs::inheritFromExprs` (by itself or in `ExprLet`), whose values are put into their own `Env`.
- */
-struct ExprInheritFrom : ExprVar
-{
-    ExprInheritFrom(PosIdx pos, Displacement displ): ExprVar(pos, {})
-    {
-        this->level = 0;
-        this->displ = displ;
-        this->fromWith = nullptr;
-    }
-
-    void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);
-};
-
 struct ExprSelect : Expr
 {
     PosIdx pos;
     Expr * e, * def;
     AttrPath attrPath;
-    ExprSelect(const PosIdx & pos, Expr * e, AttrPath attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(std::move(attrPath)) { };
+    ExprSelect(const PosIdx & pos, Expr * e, const AttrPath && attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(std::move(attrPath)) { };
     ExprSelect(const PosIdx & pos, Expr * e, Symbol name) : pos(pos), e(e), def(0) { attrPath.push_back(AttrName(name)); };
     PosIdx getPos() const override { return pos; }
     COMMON_METHODS
@@ -161,7 +248,7 @@ struct ExprOpHasAttr : Expr
 {
     Expr * e;
     AttrPath attrPath;
-    ExprOpHasAttr(Expr * e, AttrPath attrPath) : e(e), attrPath(std::move(attrPath)) { };
+    ExprOpHasAttr(Expr * e, const AttrPath && attrPath) : e(e), attrPath(std::move(attrPath)) { };
     PosIdx getPos() const override { return e->getPos(); }
     COMMON_METHODS
 };
@@ -171,40 +258,16 @@ struct ExprAttrs : Expr
     bool recursive;
     PosIdx pos;
     struct AttrDef {
-        enum class Kind {
-            /** `attr = expr;` */
-            Plain,
-            /** `inherit attr1 attrn;` */
-            Inherited,
-            /** `inherit (expr) attr1 attrn;` */
-            InheritedFrom,
-        };
-
-        Kind kind;
+        bool inherited;
         Expr * e;
         PosIdx pos;
         Displacement displ; // displacement
-        AttrDef(Expr * e, const PosIdx & pos, Kind kind = Kind::Plain)
-            : kind(kind), e(e), pos(pos) { };
+        AttrDef(Expr * e, const PosIdx & pos, bool inherited=false)
+            : inherited(inherited), e(e), pos(pos) { };
         AttrDef() { };
-
-        template<typename T>
-        const T & chooseByKind(const T & plain, const T & inherited, const T & inheritedFrom) const
-        {
-            switch (kind) {
-            case Kind::Plain:
-                return plain;
-            case Kind::Inherited:
-                return inherited;
-            default:
-            case Kind::InheritedFrom:
-                return inheritedFrom;
-            }
-        }
     };
     typedef std::map<Symbol, AttrDef> AttrDefs;
     AttrDefs attrs;
-    std::unique_ptr<std::vector<Expr *>> inheritFromExprs;
     struct DynamicAttrDef {
         Expr * nameExpr, * valueExpr;
         PosIdx pos;
@@ -217,11 +280,6 @@ struct ExprAttrs : Expr
     ExprAttrs() : recursive(false) { };
     PosIdx getPos() const override { return pos; }
     COMMON_METHODS
-
-    std::shared_ptr<const StaticEnv> bindInheritSources(
-        EvalState & es, const std::shared_ptr<const StaticEnv> & env);
-    Env * buildInheritFromEnv(EvalState & state, Env & up);
-    void showBindings(const SymbolTable & symbols, std::ostream & str) const;
 };
 
 struct ExprList : Expr
@@ -229,7 +287,6 @@ struct ExprList : Expr
     std::vector<Expr *> elems;
     ExprList() { };
     COMMON_METHODS
-    Value * maybeThunk(EvalState & state, Env & env) override;
 
     PosIdx getPos() const override
     {
@@ -316,7 +373,6 @@ struct ExprWith : Expr
     PosIdx pos;
     Expr * attrs, * body;
     size_t prevWith;
-    ExprWith * parentWith;
     ExprWith(const PosIdx & pos, Expr * attrs, Expr * body) : pos(pos), attrs(attrs), body(body) { };
     PosIdx getPos() const override { return pos; }
     COMMON_METHODS
@@ -344,7 +400,6 @@ struct ExprOpNot : Expr
 {
     Expr * e;
     ExprOpNot(Expr * e) : e(e) { };
-    PosIdx getPos() const override { return e->getPos(); }
     COMMON_METHODS
 };
 
@@ -394,30 +449,20 @@ struct ExprPos : Expr
     COMMON_METHODS
 };
 
-/* only used to mark thunks as black holes. */
-struct ExprBlackHole : Expr
-{
-    void show(const SymbolTable & symbols, std::ostream & str) const override {}
-    void eval(EvalState & state, Env & env, Value & v) override;
-    void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env) override {}
-};
-
-extern ExprBlackHole eBlackHole;
-
 
 /* Static environments are used to map variable names onto (level,
    displacement) pairs used to obtain the value of the variable at
    runtime. */
 struct StaticEnv
 {
-    ExprWith * isWith;
+    bool isWith;
     const StaticEnv * up;
 
     // Note: these must be in sorted order.
     typedef std::vector<std::pair<Symbol, Displacement>> Vars;
     Vars vars;
 
-    StaticEnv(ExprWith * isWith, const StaticEnv * up, size_t expectedSize = 0) : isWith(isWith), up(up) {
+    StaticEnv(bool isWith, const StaticEnv * up, size_t expectedSize = 0) : isWith(isWith), up(up) {
         vars.reserve(expectedSize);
     };