these 6 derivations will be built:
  /nix/store/5pnafk6qbv2s6p0s9p4vp1kx1jyxwa6l-types_icalendar-6.3.2.20260223.tar.gz.drv
  /nix/store/b55d5dxy1y43bf3ly7bidd1pp0xszvh2-python3.14-types-icalendar-6.3.2.20260223.drv
  /nix/store/fn15q9vvxnxh4ih5mdhiz79vlaqmcaqz-mdformat-wrapped.drv
  /nix/store/irv238xhykcnjm0fy1zjgplk71dgii39-treefmt.toml.drv
  /nix/store/ik8iwqyfvrsnccgd1dmfsc12pbsin8xz-treefmt.drv
  /nix/store/lh1bisj23hi9kamqdkb3mrlvjda8paw1-treefmt-check.drv
these 5 paths will be fetched (16.3 MiB download, 67.6 MiB unpacked):
  /nix/store/w3vsprzhxpq4lsk61ava6xcpa7gbyshg-python3.14-mdformat-frontmatter-2.0.10
  /nix/store/rwhsrjlbc2pjsfhjfwjsr7ksxwxpgplc-python3.14-mdit-py-plugins-0.6.1
  /nix/store/pn48p580ynnv8j1cgh44zj24qyy59nb8-python3.14-mypy-2.1.0
  /nix/store/4kwsacrhd83ch0l8jj261xm2gln978sn-python3.14-types-python-dateutil-2.9.0.20251115
  /nix/store/zxjffmgxvjbgqahzdzj9f9ggwbzfqc30-python3.14-types-pytz-2026.1.1.20260304
error: Cannot build '/nix/store/lh1bisj23hi9kamqdkb3mrlvjda8paw1-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/ilnfmcrld2zalbkaa93l9babwslc7yil-treefmt-check
       Last 25 log lines:
       >
       > CPY001 Missing copyright notice at top of file
       > --> calendar-cli/tests/test_cache.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> calendar-cli/tests/test_cli.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> calendar-cli/tests/test_import.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> calendar-cli/tests/test_invite.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> calendar-cli/tests/test_reply.py:1:1
       >
       > CPY001 Missing copyright notice at top of file
       > --> calendar-cli/tests/test_store.py:1:1
       >
       > Found 23 errors.
       >
       > traversed 363 files
       > emitted 319 files for processing
       > formatted 128 files (25 changed) in 3.238s
       > Error: failed to finalise formatting: formatting failures detected
       For full logs, run:
         nix log /nix/store/lh1bisj23hi9kamqdkb3mrlvjda8paw1-treefmt-check.drv