diff --git a/tests/functional2/build/test_fixed.py b/tests/functional2/build/test_fixed.py
index 4cedd7c1c..be627edf4 100644
--- a/tests/functional2/build/test_fixed.py
+++ b/tests/functional2/build/test_fixed.py
@@ -21,8 +21,8 @@ def impure_vars(env: ManagedEnv):
 
 @with_files(get_global_asset_pack("fixed"))
 def test_bad(nix: Nix):
-    res = nix.nix_instantiate(["fixed.nix", "-A", "good.0"], build=True).run().ok()
-    store_path = nix.nix_store(["-q", res.stdout_plain], build=True).run().ok().stdout_plain
+    res = nix.nix_instantiate(["fixed.nix", "-A", "good.0"]).run().ok()
+    store_path = nix.nix_store(["-q", res.stdout_plain]).run().ok().stdout_plain
     path = Path(store_path)
     assert not path.exists()
 
@@ -33,7 +33,7 @@ def test_bad(nix: Nix):
     assert path.exists()
 
     nix.settings.add_xp_feature("nix-command")
-    res = nix.nix(["path-info", "--json", store_path], build=True).run().ok()
+    res = nix.nix(["path-info", "--json", store_path]).run().ok()
     assert res.json()[0]["ca"] == "fixed:md5:2qk15sxzzjlnpjk9brn7j8ppcd"
 
 
diff --git a/tests/functional2/build/test_substitution.py b/tests/functional2/build/test_substitution.py
index 9dda147b1..7ad24e7e1 100644
--- a/tests/functional2/build/test_substitution.py
+++ b/tests/functional2/build/test_substitution.py
@@ -19,7 +19,7 @@ def build(nix: Nix, *args) -> CommandResult:
             outputHash = "sha256-AbpHGcgLb+kRsJGnwFEktk7uzpZOCcBY74+YBdrKVGs=";
         }
     """
-    return nix.nix_build(["-E", expr, "--no-link", "--no-require-sigs", *args], build=True).run()
+    return nix.nix_build(["-E", expr, "--no-link", "--no-require-sigs", *args]).run()
 
 
 @dataclasses.dataclass
diff --git a/tests/functional2/commands/test_build/test_build_fod.py b/tests/functional2/commands/test_build/test_build_fod.py
index 0cea00f76..602f222fc 100644
--- a/tests/functional2/commands/test_build/test_build_fod.py
+++ b/tests/functional2/commands/test_build/test_build_fod.py
@@ -85,7 +85,6 @@ def test_build_inaccessible_build_dir(nix: Nix):
                 "--no-link",
             ],
             flake=True,
-            build=True,
         ).run().ok()
     finally:
         # clean up perms
diff --git a/tests/functional2/commands/test_build/test_build_multiple_outputs.py b/tests/functional2/commands/test_build/test_build_multiple_outputs.py
index 839ec1ac4..68e0db250 100644
--- a/tests/functional2/commands/test_build/test_build_multiple_outputs.py
+++ b/tests/functional2/commands/test_build/test_build_multiple_outputs.py
@@ -142,7 +142,7 @@ def test_build_unsafe_discard(nix: Nix):
 def drv(nix: Nix) -> str:
     nix.settings.add_xp_feature("nix-command")
     return (
-        nix.nix(["eval", "-f", "multiple-outputs.nix", "--raw", "a.drvPath"], build=True)
+        nix.nix(["eval", "-f", "multiple-outputs.nix", "--raw", "a.drvPath"])
         .run()
         .ok()
         .stdout_plain
diff --git a/tests/functional2/commands/test_build/test_reference_checks.py b/tests/functional2/commands/test_build/test_reference_checks.py
index 30234a9d0..5636addc8 100644
--- a/tests/functional2/commands/test_build/test_reference_checks.py
+++ b/tests/functional2/commands/test_build/test_reference_checks.py
@@ -20,7 +20,7 @@ def test_references_detected(nix: Nix):
     )
 
     refs_test1, refs_test2 = (
-        nix.nix_store(["-q", "--references", path], build=True).run().ok().stdout_plain.splitlines()
+        nix.nix_store(["-q", "--references", path]).run().ok().stdout_plain.splitlines()
         for path in [test1, test2]
     )
 
@@ -92,12 +92,7 @@ def test_disallowed_references(nix: Nix):
 def test_structured_attrs_discard(nix: Nix):
     result = nix.nix_build(["check-refs.nix", "-A", "test11"]).run().ok().stdout_plain.splitlines()
 
-    assert not (
-        nix.nix_store(["-q", "--references", *result], build=True)
-        .run()
-        .ok()
-        .stdout_plain.splitlines()
-    )
+    assert not (nix.nix_store(["-q", "--references", *result]).run().ok().stdout_plain.splitlines())
 
 
 @with_files(_files)
@@ -127,6 +122,6 @@ def test_regression_partial_build(nix: Nix):
         .stdout_plain.splitlines()
     )
 
-    nix.nix_store(["--delete", out], build=True).run().ok()
+    nix.nix_store(["--delete", out]).run().ok()
 
     nix.nix_build(["regression-reference-checks.nix", "-A", "out"]).run().ok()
diff --git a/tests/functional2/commands/test_build/test_tarball.py b/tests/functional2/commands/test_build/test_tarball.py
index 9be87cf0b..58d435ac2 100644
--- a/tests/functional2/commands/test_build/test_tarball.py
+++ b/tests/functional2/commands/test_build/test_tarball.py
@@ -59,7 +59,7 @@ def tarball(request: FixtureRequest, nix: Nix, files: Path) -> Path:
     )
     tarball_path.write_bytes(tarball_content)
 
-    res = nix.nix_env(["-f", f"file://{tarball_path}", "-qa", "--out-path"], build=True).run().ok()
+    res = nix.nix_env(["-f", f"file://{tarball_path}", "-qa", "--out-path"]).run().ok()
     assert "dependencies" in res.stdout_plain
 
     return tarball_path
@@ -154,7 +154,6 @@ def test_last_modified(nix: Nix, tarball: Path):
         nix.nix(
             ["eval", "--impure", "--expr", f'(fetchTree "file://{tarball}").lastModified'],
             flake=True,
-            build=True,
         )
         .run()
         .ok()
@@ -189,7 +188,6 @@ def test_no_submodules(nix: Nix, tarball: Path, tar_hash: str):
                 f'!((fetchTree {{ type = "tarball"; url = "file://{tarball}"; narHash = "{tar_hash}"; }})) ? submodules',
             ],
             flake=True,
-            build=True,
         )
         .run()
         .ok()
diff --git a/tests/functional2/commands/test_why_depends.py b/tests/functional2/commands/test_why_depends.py
index f0c32a68f..8f9674905 100644
--- a/tests/functional2/commands/test_why_depends.py
+++ b/tests/functional2/commands/test_why_depends.py
@@ -9,12 +9,9 @@ def test_command_doesnt_crash(nix: Nix):
     nix.nix(
         ["why-depends", "--derivation", "--file", "./dependencies.nix", "input2_drv", "input1_drv"],
         flake=True,
-        build=True,
     ).run().ok()
     nix.nix(
-        ["why-depends", "--file", "./dependencies.nix", "input2_drv", "input1_drv"],
-        flake=True,
-        build=True,
+        ["why-depends", "--file", "./dependencies.nix", "input2_drv", "input1_drv"], flake=True
     ).run().ok()
 
 
@@ -27,7 +24,7 @@ def built_files(nix: Nix):
 @with_files(get_global_asset_pack("dependencies"))
 def test_fast_depends(nix: Nix):
     built_files(nix)
-    res = nix.nix(["why-depends", "./toplevel", "./dep"], flake=True, build=True).run().ok()
+    res = nix.nix(["why-depends", "./toplevel", "./dep"], flake=True).run().ok()
     assert "input-2" in res.stdout_plain
     assert "reference-to-input-2" not in res.stdout_plain
 
@@ -35,11 +32,7 @@ def test_fast_depends(nix: Nix):
 @with_files(get_global_asset_pack("dependencies"))
 def test_precise_depends(nix: Nix):
     built_files(nix)
-    res = (
-        nix.nix(["why-depends", "./toplevel", "./dep", "--precise"], flake=True, build=True)
-        .run()
-        .ok()
-    )
+    res = nix.nix(["why-depends", "./toplevel", "./dep", "--precise"], flake=True).run().ok()
     out = res.stdout_plain
     assert "input-2" in out
     assert "reference-to-input-2" in out
@@ -53,7 +46,7 @@ def test_precise_depends(nix: Nix):
 @with_files(get_global_asset_pack("dependencies"))
 def test_self_ref(nix: Nix):
     built_files(nix)
-    res = nix.nix(["why-depends", "./toplevel", "./toplevel"], flake=True, build=True).run().ok()
+    res = nix.nix(["why-depends", "./toplevel", "./toplevel"], flake=True).run().ok()
     lines = res.stdout_plain.splitlines()
     assert "dependencies-top" in lines[0]
     assert "dependencies-top" in lines[1]
@@ -62,9 +55,7 @@ def test_self_ref(nix: Nix):
 @with_files(get_global_asset_pack("dependencies"))
 def test_all(nix: Nix):
     built_files(nix)
-    res = (
-        nix.nix(["why-depends", "./toplevel", "./dep3", "--all"], flake=True, build=True).run().ok()
-    )
+    res = nix.nix(["why-depends", "./toplevel", "./dep3", "--all"], flake=True).run().ok()
     lines = res.stdout_plain.splitlines()
     assert "dependencies-top" in lines[0]
     assert "input-2" in lines[1]
diff --git a/tests/functional2/store/cache/test_compression_levels.py b/tests/functional2/store/cache/test_compression_levels.py
index 0ce2c82cb..1000c7bca 100644
--- a/tests/functional2/store/cache/test_compression_levels.py
+++ b/tests/functional2/store/cache/test_compression_levels.py
@@ -23,8 +23,7 @@ def test_compression_levels(nix: Nix):
                     "--to",
                     f"file://{c_dir}?compression=xz&compression-level={level}",
                     out_path,
-                ],
-                build=True,
+                ]
             )
             .run()
             .ok()
diff --git a/tests/functional2/store/cache/test_substitute_truncated_nar.py b/tests/functional2/store/cache/test_substitute_truncated_nar.py
index fd2338beb..16354626b 100644
--- a/tests/functional2/store/cache/test_substitute_truncated_nar.py
+++ b/tests/functional2/store/cache/test_substitute_truncated_nar.py
@@ -25,7 +25,7 @@ def test_substitute_truncated_nar(nix: Nix):
 
     assert nar.exists()
 
-    res = nix.nix([], "nix-collect-garbage", build=True).run().ok()
+    res = nix.nix([], "nix-collect-garbage").run().ok()
     # .drv file + built path
     assert "2 store paths deleted" in res.stderr_plain
 
diff --git a/tests/functional2/store/test_dump_db.py b/tests/functional2/store/test_dump_db.py
index 9b3843327..cc44504dc 100644
--- a/tests/functional2/store/test_dump_db.py
+++ b/tests/functional2/store/test_dump_db.py
@@ -9,22 +9,22 @@ from testlib.utils import get_global_asset_pack
 def test_dump_db(nix: Nix):
     nix.nix_build(["dependencies.nix", "-o", "result"]).run().ok()
 
-    res = nix.nix_store(["-qR", "result"], build=True).run().ok()
+    res = nix.nix_store(["-qR", "result"]).run().ok()
     deps = res.stdout_plain
 
-    res = nix.nix_store(["--dump-db"], build=True).run().ok()
+    res = nix.nix_store(["--dump-db"]).run().ok()
     dump = res.stdout
 
     shutil.rmtree(nix.env.dirs.nix_state_dir / "db")
 
-    nix.nix_store(["--load-db"], build=True).with_stdin(dump).run().ok()
+    nix.nix_store(["--load-db"]).with_stdin(dump).run().ok()
 
-    res = nix.nix_store(["-qR", "result"], build=True).run().ok()
+    res = nix.nix_store(["-qR", "result"]).run().ok()
     deps2 = res.stdout_plain
 
     assert deps == deps2
 
-    res = nix.nix_store(["--dump-db"], build=True).run().ok()
+    res = nix.nix_store(["--dump-db"]).run().ok()
     dump2 = res.stdout
 
     assert dump == dump2
diff --git a/tests/functional2/testlib/fixtures/nix.py b/tests/functional2/testlib/fixtures/nix.py
index ab210db3b..8bfe58791 100644
--- a/tests/functional2/testlib/fixtures/nix.py
+++ b/tests/functional2/testlib/fixtures/nix.py
@@ -4,7 +4,7 @@ import dataclasses
 import sys
 from functools import partialmethod
 from pathlib import Path
-from typing import Any, Literal
+from typing import Any
 from collections.abc import Callable, Generator
 import shutil
 import subprocess
@@ -155,12 +155,7 @@ class Nix:
 
         return self._settings
 
-    def nix_cmd(
-        self,
-        argv: list[str],
-        flake: bool = False,
-        build: bool | Literal["auto"] = "auto",  # noqa: ARG002
-    ) -> Command:
+    def nix_cmd(self, argv: list[str], flake: bool = False) -> Command:
         """
         Constructs a NixCommand with the appropriate settings.
         :param build: if the executed command wants to build stuff. This is required due to darwin shenanigans. "auto" will try to autodetect, override using `True` or `False`. Has no effect on linux.
@@ -173,14 +168,8 @@ class Nix:
         settings.to_env_overlay(self.env)
         return Command(argv=argv, exe=self._nix_executable, _env=self.env)
 
-    def nix(
-        self,
-        cmd: list[str],
-        nix_exe: str = "nix",
-        flake: bool = False,
-        build: bool | Literal["auto"] = "auto",
-    ) -> Command:
-        return self.nix_cmd([nix_exe, *cmd], flake=flake, build=build)
+    def nix(self, cmd: list[str], nix_exe: str = "nix", flake: bool = False) -> Command:
+        return self.nix_cmd([nix_exe, *cmd], flake=flake)
 
     @contextlib.contextmanager
     def daemon(