this package seems to have new commits in its VCS but has
not yet updated debian/changelog. You should consider updating
the Debian changelog and uploading this new version into the archive.
Here are the relevant commit logs:
Author: Markus Koschany <firstname.lastname@example.org>
Date: Sat Nov 10 15:19:17 2018 +0100
Add StartupWMClass=cube2_client to sauerbraten.desktop to make the icon visible
in window manager dock applications.