these 3 derivations will be built:
  /nix/store/7rnb8hb158zl6p269dar7q3bzff3nb5a-treefmt.toml.drv
  /nix/store/7sjbyn69iz3hjs2farqvhr0rlyym9zgr-treefmt.drv
  /nix/store/yh0lf43sy3155wir62hxwpgv7mwyjrz0-treefmt-check.drv
this path will be fetched (16.9 MiB download, 69.3 MiB unpacked):
  /nix/store/vch39793cw5n51cwjm6qqkjgji4slaws-python3.14-mypy-2.3.1
error: Cannot build '/nix/store/yh0lf43sy3155wir62hxwpgv7mwyjrz0-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/i7f3wmklh7j6w04fl1zxsv9ls4jwbhpf-treefmt-check
       Last 25 log lines:
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_benchmark.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_cli.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_command.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_git_revision.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_parser.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_specs.py:1:1
       >
       > Found 17 errors.
       >
       > traversed 31 files
       > emitted 22 files for processing
       > formatted 5 files (0 changed) in 1.191s
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/yh0lf43sy3155wir62hxwpgv7mwyjrz0-treefmt-check.drv