this derivation will be built:
  /nix/store/sk830h5z8jghbyqbgk2bgxf8pkn15pvn-nix-eval-warnings-0.1.0.drv
error: Cannot build '/nix/store/sk830h5z8jghbyqbgk2bgxf8pkn15pvn-nix-eval-warnings-0.1.0.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/hkrrmgj2q7r4lpfcfg0dadz1dm9lpyp6-nix-eval-warnings-0.1.0-dist
         /nix/store/sdzp72gsk4mskhn9qr8z21sc5vsdbpcl-nix-eval-warnings-0.1.0
       Last 25 log lines:
       > rootdir: /build/nix-eval-warnings
       > configfile: pyproject.toml
       > collected 12 items
       >
       > tests/test_nix_eval_warnings.py ..F.........                             [100%]
       >
       > =================================== FAILURES ===================================
       > ____ TestNixEvalWarningsIntegration.test_source_location_has_file_and_line _____
       >
       > self = <tests.test_nix_eval_warnings.TestNixEvalWarningsIntegration testMethod=test_source_location_has_file_and_line>
       >
       >     def test_source_location_has_file_and_line(self) -> None:
       >         """Test that source file and line number are extracted."""
       >         for w in self.warnings:
       > >           assert "flake.nix:" in w.source, (
       >                 f"Expected 'flake.nix:' in source, got: {w.source}"
       >             )
       > E           AssertionError: Expected 'flake.nix:' in source, got:
       > E           assert 'flake.nix:' in ''
       > E            +  where '' = EvalWarning(attr='x86_64-linux.uses-input', warning_type='warning from subflake', source='', option_path='').source
       >
       > tests/test_nix_eval_warnings.py:169: AssertionError
       > =========================== short test summary info ============================
       > FAILED tests/test_nix_eval_warnings.py::TestNixEvalWarningsIntegration::test_source_location_has_file_and_line
       > ========================= 1 failed, 11 passed in 0.28s =========================
       For full logs, run:
         nix log /nix/store/sk830h5z8jghbyqbgk2bgxf8pkn15pvn-nix-eval-warnings-0.1.0.drv