these 3 derivations will be built:
  /nix/store/8j5sa0sszx8i4hwp00ab5wiirn0l47gd-treefmt.toml.drv
  /nix/store/pshgiq4rcd4lpa18snay6d77gywpj27g-treefmt.drv
  /nix/store/jb6lz3nx18jlsjcpi2xg5sh2b8fcbq02-treefmt-check.drv
this path will be fetched (15.3 MiB download, 81.7 MiB unpacked):
  /nix/store/8y7qng20qjpl2c2fswngxa36v9k63qac-python3.14-mypy-2.1.0
error: Cannot build '/nix/store/jb6lz3nx18jlsjcpi2xg5sh2b8fcbq02-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/sls4f1pjh8fjn1j7lys1pai8mb7yp67b-treefmt-check
       Last 25 log lines:
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_update.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_version_compare.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_version_prefix.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_version_regex_no_rev.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_version_sorting.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> tests/test_yarn_berry_missing_hashes.py:1:1
       >
       > Found 79 errors (2 fixed, 77 remaining).
       >
       > traversed 158 files
       > emitted 143 files for processing
       > formatted 66 files (0 changed) in 115ms
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/jb6lz3nx18jlsjcpi2xg5sh2b8fcbq02-treefmt-check.drv