these 3 derivations will be built:
  /nix/store/13alkhmyhcapcdnp1fk3fynfmdxlg65s-treefmt.toml.drv
  /nix/store/aallbhvcj9kmxgdg5vfi53sivc5rysln-treefmt.drv
  /nix/store/yxjisf1810k445ni11zli3ggmwjvdfbv-treefmt-check.drv
these 7 paths will be fetched (15.3 MiB download, 74.1 MiB unpacked):
  /nix/store/ryiyvk5i3pbwfc9k4ajaky4bs6wnrrc1-python3.14-ast-serialize-0.6.0
  /nix/store/h6bypg03d8gpxg79ichx9j29z8k3k65i-python3.14-flit-core-3.12.0
  /nix/store/k5d9rqgrj36q0saj27j2g3h25safy62x-python3.14-librt-0.13.0
  /nix/store/7vqdb1lf3y2f0c19axcffb2hpvi4jndc-python3.14-mypy-2.3.1
  /nix/store/g2z8g5h96ympbr6rgad0qqhmrab7vgf9-python3.14-mypy-extensions-1.1.0
  /nix/store/ppbivbfh3zsh7zy4mvpd7vi2jksa7zfj-python3.14-pathspec-1.1.1
  /nix/store/9f5invlkccxdbh4ckgzz2hkb3va73f8p-python3.14-typing-extensions-4.16.0
error: Cannot build '/nix/store/yxjisf1810k445ni11zli3ggmwjvdfbv-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/n92ffh1p72a1hh8j7d05038z215jl3gg-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 (15 changed) in 787ms
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/yxjisf1810k445ni11zli3ggmwjvdfbv-treefmt-check.drv