I find it confusing that libcupsfilters2-common is v3, not v2!
So the problematic package appears to be: * Package: cpdb-backend-cups * Maintainer: Thorsten Alteholz <debian@alteholz.de> * Depends: ..., libcupsfilters2 (>= 2.0.0), ... And it is Recommended by libgtk-4-1.