these 3 derivations will be built:
  /nix/store/cjr8sqzy3hb4w8gv1hm92ivhy3gqhkxd-treefmt.toml.drv
  /nix/store/4s9gma9v2r0fzn1cfdga9yxxxzg5m4mr-treefmt.drv
  /nix/store/21sszlnbpr9rckz8z3l7mwcicj1h6fm8-treefmt-check.drv
this path will be fetched (16.6 MiB download, 68.2 MiB unpacked):
  /nix/store/qvyjj82swpjclzyld9j3fffhbjhmgyzq-python3.14-mypy-2.1.0
error: Cannot build '/nix/store/21sszlnbpr9rckz8z3l7mwcicj1h6fm8-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/620sixs4xna16v7nl8skw0cbnfll9lnh-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 3.153s
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/21sszlnbpr9rckz8z3l7mwcicj1h6fm8-treefmt-check.drv