these 3 derivations will be built:
  /nix/store/kjsmckhkjqnd176n5f174nn6f408qxqn-treefmt.toml.drv
  /nix/store/w1axa8a7bajhrs0r0518521qpdn8713n-treefmt.drv
  /nix/store/cb7p5mb3rhi3hgfvvar7wwn9rs6br3ka-treefmt-check.drv
these 6 paths will be fetched (17.0 MiB download, 86.6 MiB unpacked):
  /nix/store/j6n13s46cba7i89jadqhl9zgzj3i0rqq-python3.14-ast-serialize-0.6.0
  /nix/store/b8smqhbvs6imvfgxf4xhrajwai1djp6a-python3.14-flit-core-3.12.0
  /nix/store/bhhd8kmbayxb0lm6k7g0lsgfi5dmsbyw-python3.14-librt-0.13.0
  /nix/store/rsb9h6mqbibbs04zikcfwqzmn8cw625w-python3.14-mypy-2.3.1
  /nix/store/8fwyiwqick7a2m7ni2ni0blrjgzcv4nq-python3.14-mypy-extensions-1.1.0
  /nix/store/9p8x7513rkbsxpwd6g712fn0pqwrldzi-python3.14-pathspec-1.1.1
error: Cannot build '/nix/store/cb7p5mb3rhi3hgfvvar7wwn9rs6br3ka-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/37lmnaq118s84wqjh4rdk5px60ykc6h5-treefmt-check
       Last 25 log lines:
       >     |
       > 193 |         return " ".join(parts).encode("utf-8")
       > 194 |
       > 195 |     def _write_command(self, command: str, args: list[str] = []) -> None:
       >     |                                                              ^^
       > 196 |         self.sendLine(self._create_command(command, args))
       >     |
       > help: Replace with `None`; initialize within function
       >     |
       > 194 |
       >     -     def _write_command(self, command: str, args: list[str] = []) -> None:
       > 195 +     def _write_command(self, command: str, args: list[str] = None) -> None:
       > 196 +         if args is None:
       > 197 +             args = []
       > 198 |         self.sendLine(self._create_command(command, args))
       >     |
       > note: This is an unsafe fix and may change runtime behavior
       >
       > Found 298 errors (242 fixed, 56 remaining).
       > 33 unsafe fixes available with `--fix --unsafe-fixes`.
       >
       > traversed 45 files
       > emitted 18 files for processing
       > formatted 0 files (14 changed) in 124ms
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/cb7p5mb3rhi3hgfvvar7wwn9rs6br3ka-treefmt-check.drv