@buhtz One of the Travis CI builds did not succeed (looks like a connection timeout). Do you have the rights to trigger the build again to be sure no unit test is failing in our build matrix? THX!

$ git clone --depth=50 https://github.com/bit-team/backintime.git bit-team/backintime
No output has been received in the last 10m0s, this potentially indicates a stalled build
or something wrong with the build itself.
...
The build has been terminated

You had a long night. 👍

About TravisCI: The problem is known but not understood yet. Happens only on "ppc64le" machine. I retriggered and it worked now. The Travis support told me to logout and login again. That worked also. If this happens more often I will recontact the support. But maybe we should switch from Ubuntu20 to Ubuntu22 after the Debian release.
You can create your own TravisCI account if you want. I assume the GitHub-Team-setup is reflected in Travis and you should be able to trigger builds then.

About your PR: Looks OK for me but I'm not a keyring user or pro. My review isn't much of a value. I would only say the code is not PEP8 conform (e.g. length of lines). But we have bigger "problems". 😄

I would only say the code is not PEP8 conform (e.g. length of lines)

Yes, I have to admit I quite often ignore the PEP8 max length of line rule for better readability (my quite personal and biased opinion ;-)

I am merging now, for Debian a PR containing this code as patch is on its way:

https://salsa.debian.org/jmw/pkg-backintime/-/merge_requests/9