Merge changes I577bdc15,I1c5f7a5c,I75f56c80 into release-2.92

* changes:
  version: 2.92.1
  release-notes: note the flake.lock fix
  libexpr/flake: user friendly error if parsing flake.lock fails

doc/manual/change-authors.yml

@@ -62,6 +62,9 @@ ericson:
   display_name: John Ericson
   github: ericson2314
 
+gilice:
+  forgejo: gilice
+
 goldstein:
   display_name: goldstein
   forgejo: goldstein

doc/manual/rl-next/flake-lockfile-crash.md

@@ -0,0 +1,18 @@
+---
+synopsis: "Parsing failures in flake.lock no longer crash Lix"
+issues: [fj#559]
+cls: [2401]
+category: "Fixes"
+credits: ["gilice"]
+---
+Failure to parse `flake.lock` no longer hard-crashes Lix and instead produces a nice error message.
+
+```
+error:
+       … while updating the lock file of flake 'git+file:///Users/jade/lix/lix2'
+
+       … while parsing the lock file at /nix/store/mm5dqh8a729yazzj82cjffxl97n5c62s-source//flake.lock
+
+       error: [json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - invalid literal;
+ last read: '#'
+```

lix/libexpr/flake/lockfile.cc

@@ -1,5 +1,7 @@
 #include "lix/libexpr/flake/lockfile.hh"
+#include "json-to-value.hh"
 #include "lix/libstore/store-api.hh"
+#include "lix/libutil/error.hh"
 #include "lix/libutil/url-parts.hh"
 
 #include <iomanip>
@@ -186,8 +188,16 @@ std::string LockFile::to_string() const
 
 LockFile LockFile::read(const Path & path)
 {
-    if (!pathExists(path)) return LockFile();
+    if (!pathExists(path)) {
+        return LockFile();
+    }
+    try {
         return LockFile(nlohmann::json::parse(readFile(path)), path);
+    } catch (nlohmann::json::parse_error &nlohmann_json_parse_exc) {
+       auto json_parse_error = JSONParseError(nlohmann_json_parse_exc.what());
+       json_parse_error.addTrace(nullptr, "while parsing the lock file at %s", path);
+       throw json_parse_error;
+    }
 }
 
 std::ostream & operator <<(std::ostream & stream, const LockFile & lockFile)

tests/functional2/flakes/test_invalid_flake_lock.py

@@ -0,0 +1,30 @@
+from pathlib import Path
+from textwrap import dedent
+from functional2.testlib.fixtures import Nix
+import re
+
+def test_invalid_flake_lock(nix: Nix, tmp_path: Path):
+    flake_dir = tmp_path / 'flake'
+    flake_dir.mkdir()
+
+    (flake_dir / 'flake.nix').write_text(dedent("""
+        {
+            inputs = {};
+            outputs = inputs: {};
+        }
+    """))
+    (flake_dir / 'flake.lock').write_text(dedent("""
+        {
+            this flake.lock is obviously invalid
+        }
+    """))
+
+    cmd = nix.nix(["build"], flake=True)
+    cmd.cwd = flake_dir
+    res = cmd.run().expect(1)
+    print(res.stderr_plain)
+
+    ERROR_RE1 = re.compile(fr"while updating the lock file of flake 'path:{flake_dir}.+'")
+    ERROR_RE2 = re.compile(fr"while parsing the lock file at .+")
+    assert ERROR_RE1.search(res.stderr_plain)
+    assert ERROR_RE2.search(res.stderr_plain)

version.json

@@ -1,5 +1,5 @@
 {
-    "version": "2.92.0",
+    "version": "2.92.1",
     "official_release": false,
     "release_name": "Bombe glacée"
 }