these 3 derivations will be built:
  /nix/store/yqwwffmcwybwqrd6p3dzsr86kbhc10bj-treefmt.toml.drv
  /nix/store/mgm327m57l1y21fc7cgc8mqwkgbpyfii-treefmt.drv
  /nix/store/7cn1r1r6cw69w8qc466hy0bsi3ys2mhc-treefmt-check.drv
these 6 paths will be fetched (18.4 MiB download, 73.3 MiB unpacked):
  /nix/store/jd16vchsy8r1f51vf0nivz3pdj0jkf44-python3.14-ast-serialize-0.6.0
  /nix/store/4vv3gbdl6fa3llqvhc7j7gbdsfs34j9n-python3.14-flit-core-3.12.0
  /nix/store/p3q4awbgrr7dqz715pc87qasi0by01ys-python3.14-librt-0.13.0
  /nix/store/vch39793cw5n51cwjm6qqkjgji4slaws-python3.14-mypy-2.3.1
  /nix/store/rk1ja5v0xc12sqd3kcjmp0s5b16gmzmn-python3.14-mypy-extensions-1.1.0
  /nix/store/f1wq43mpwfszfl8vhc2m9s1sw45fhazl-python3.14-pathspec-1.1.1
error: Cannot build '/nix/store/7cn1r1r6cw69w8qc466hy0bsi3ys2mhc-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/nnif7phynmpixa7vmf60n2qkygxfrx8n-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 180ms
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/7cn1r1r6cw69w8qc466hy0bsi3ys2mhc-treefmt-check.drv