Thanks for letting me know. I'm not notified of changeset pushes.. only comments.
Formal documentation probably isn't necessary for this feature given that it's "documented" in the configuration schema. However, adding some basic tests would be welcome if you're up to it. The file to add tests to is tests/unit/commands/test_borgmatic.py, and the test doesn't have to be super involved.. Just getting some basic coverage would be good. I would expect the actual locking to be mocked out!
If adding tests for this is too much, let me know and I can take a crack at it.
Why not using a more pythonic way of opening the file? Currently the file resource is also never closed and is a bad practice.
Instead of lock_f = open(config_filename), use with open(config_filename) as lock_f:.
This pull request has changes conflicting with the target branch.