Comment 1 for bug 1999897

If calling autogen.sh in the bionic branch, there is another discrepancy: it wants gnome-common to be installed as a build-dep, but that is not declared in d/control.

It was dropped[1] in later commits to other branches. For example, focal:

commit 38a5a75dcd3586cda0cf8d2401053825f024c497
Author: Sebastien Bacher <email address hidden>
Date: Tue Mar 19 11:17:55 2019 +0100

    * debian/control, autogen.sh:
      - don't build-depends on gnome-common, that is deprecated and was
        comment out in the autogen.sh already anyway

1. https://git.launchpad.net/update-notifier/commit/?id=38a5a75dcd3586cda0cf8d2401053825f024c497