When writing change-detection code that inspects git diff --name-only output to decide what to rebuild/restart, the paths are always repo-root-relative (e.g. fsrv/alembic/versions/foo.py), not relative to the Python source file or any other anchor.
A real bug: code in fsrv/src/fsrv/mirror.py checked f.startswith('fsrv/src/fsrv/alembic/versions/') against git diff output, but git reports the path as fsrv/alembic/versions/... — the src/fsrv/ segment is part of the Python package layout (src-layout), not part of the git path. The migration-detection branch never triggered.
The fix is trivial once spotted, but the bug is silent: no error, no crash, just a feature (auto-migrate on pull) that quietly never fires. Caught only during a directory rename audit that forced reading every path reference.
Rule of thumb: when comparing against git output, trace the path from the repo root on disk, not from the Python module's __file__. Test change-detection code by printing the actual git output and verifying your prefix matches.