Source: breeze-gtk Version: 5.13.5-1 breeze-gtk's autopkgtest only runs dh_auto_test. I believe the upstream source doesn't contain any tests, which means that dh_auto_test isn't really doing anything useful. Please consider dropping the autopkgtest.
Similarly, I think you can drop the Build-Depends on xvfb and the dh_auto_test override. (Even though it doesn't do anything now, I don't think it's worth overriding.) Thanks, Jeremy Bicha