Code review comment for lp://qastaging/~unit193/ubuntu-release-upgrader/core-upgrades

Sure, they don't seed that exact package, but both install and use it by installing update-manager as you can see http://cdimage.ubuntu.com/lubuntu/daily-live/current/vivid-desktop-i386.manifest and http://cdimage.ubuntu.com/xubuntu/daily-live/current/vivid-desktop-i386.manifest.

Both seeds/metas have a package and task called $flavor-core, so a user can optionally install only the minimal DE and default config. Currently when you upgrade, as expected $flavor-desktop is pulled in but as the user only wanted the bare minimum of defaults, this is highly undesired.

Yes, you are right there, I added Lubuntu support later after working out with the Xubuntu team how best to do it. Perhaps lubuntu-artwork or lubuntu-default-session would be a better target for that core.

Also, sorry for messing up the merge, seems there's some conflicts.