DistUpgrade.cfg can also contain a KeepInstalledPkgs section which I tested and works e.g.
[ubuntu-gnome-desktop] KeyDependencies=ubuntu-gnome-default-settings, ubuntu-gnome-wallpapers KeepInstalledPkgs=system-config-printer-gnome
While it'd be good to fix ubuntu-gnome-desktop to again depend on s-c-p-gnome I think using KeepInstalledPkgs might be easier.
DistUpgrade.cfg can also contain a KeepInstalledPkgs section which I tested and works e.g.
[ubuntu- gnome-desktop] =ubuntu- gnome-default- settings, ubuntu- gnome-wallpaper s gs=system- config- printer- gnome
KeyDependencies
KeepInstalledPk
While it'd be good to fix ubuntu- gnome-desktop to again depend on s-c-p-gnome I think using KeepInstalledPkgs might be easier.