How to develop on borgmatic

Source code

To get set up to hack on borgmatic, first clone master via HTTPS or SSH:

git clone


git clone ssh://

Then, install borgmatic "editable" so that you can run borgmatic commands while you're hacking on them to make sure your changes work.

cd borgmatic/
pip3 install --editable --user .

Note that this will typically install the borgmatic commands into ~/.local/bin, which may or may not be on your PATH. There are other ways to install borgmatic editable as well, for instance into the system Python install (so without --user, as root), or even into a virtualenv. How or where you install borgmatic is up to you, but generally an editable install makes development and testing easier.

Automated tests

Assuming you've cloned the borgmatic source code as described above, and you're in the borgmatic/ working copy, install tox, which is used for setting up testing environments:

sudo pip3 install tox

Finally, to actually run tests, run:

cd borgmatic

Code formatting

If when running tests, you get an error from the Black code formatter about files that would be reformatted, you can ask Black to format them for you via the following:

tox -e black

End-to-end tests

borgmatic additionally includes some end-to-end tests that integration test with Borg for a few representative scenarios. These tests don't run by default because they're relatively slow and depend on Borg. If you would like to run them:

tox -e end-to-end

Code style

Start with PEP 8. But then, apply the following deviations from it:

borgmatic code uses the Black code formatter and Flake8 code checker, so certain code style requirements will be enforced when running automated tests. See the Black and Flake8 documentation for more information.