autoremoval of deps for some metapackage section packages

[Jordan Mantha]

Hi all,

I'd like to get some input on a problem I'm facing in Edubuntu. We use
gnome-app-install as an installation GUI for the Ubuntu Education
Edition Addon CD. Besides edubuntu-desktop we also provide some
edubuntu-addon-* metapackages to help people install specific groups
of packages from the CD. For instance, edubuntu-addon-young can be
used to install just the educational applications for younger
(pre-school generally) children.

The issue is that currently if you remove one of these metapackages
from gnome-app-install it only removes the metapackage itself. The
dependencies are neither removed nor marked for auto-removal (via apt
or synaptic). This is because of the Never-MarkAuto-Sections APT
config option, which is used to prevent removal of packages when
ubuntu-desktop is removed.  While it makes quite a bit of sense for
*-desktop it's not helpful in some cases, such as my edubuntu-addon-*
packages.

So here's the options I can think of:

1) Have a gnome-app-install flag in .desktop files such as
X-AppInstall-MetaAutoRemove that would tell gnome-app-install to treat
the package as it would any other. Essentially overriding
Never-MarkAuto-Sections on a per-package basis

2) Move edubuntu-addon-* and any other such package were
Never-MarkAuto-Sections is a problem out of the metapackages section
of the archive.

Option 2 is definitely less invasive, which is good for this point in
the release cycle, but seems a bit more like a workaround than a fix
to me. One thing we probably should do anyway, is document somewhere,
Ubuntu Policy perhaps, that packages in the metapackage section are
treated differently by APT and how so.

Option 1 seems fairly easy to implement but overkill if
edubuntu-addon-* would be the only packages benefiting.

Steve Langasek asked that I get feedback on the options before we make
any decision on Option 1 vs 2. So, any thoughts? I'm particularly
interested if any other teams would find Option 1 useful.

-Jordan

-- 
"That's all very well in practice, but will it ever work in theory?" -- G. Hill
"A tidy laboratory means a lazy chemist." -- Jöns Jacob Berzelius