Smarter overrides (was Re: [packageset] Please add an ubuntu-desktop exception for gnome-shell and gnome-control-center)

[Mathieu Trudel-Lapierre]

On Thu, Jun 27, 2019 at 6:24 AM Iain Lane <laney at ubuntu.com> wrote:
>
> Thanks for handling this so far Mathieu.
>
> On Tue, Jun 25, 2019 at 09:35:04AM -0400, Mathieu Trudel-Lapierre wrote:
> > > Why isn't gnome-shell in ubuntu-desktop? I think this is due to the 'no
> > > sharing with Kubuntu' rule² causing it to be excluded transitively via
> > > screen-resolution-extra. If that's right, it seems incidental to me.
> > > This package is maintained by the Desktop team, and so I think an
> >
> > It might well be. I thought I had added an exception because I noticed
> > some of these obviously desktop packages were ending up in the wrong
> > packageset. I think the net effect is that right now they must have
> > ended up in 'desktop-core', and I had figured it was sufficient (based
> > on other packages that also end up there). I can rearrange them.
>
> No, I'm sorry, I had misunderstood the rule. It isn't 'no sharing with
> Kubuntu' - it is 'no other flavours can share with Ubuntu or Kubuntu'.
> They can share with each other just fine. The problem is that
> gnome-shell ends up in 'desktop-common' after germinating, which maps to
> the desktop-core packageset per the script (that seems correct, and
> germinate seems to be behaving rationally too).
>
> Actually quite a few other desktop packages end up out of the
> ubuntu-desktop set due to this:
>
>   https://people.canonical.com/~ubuntu-archive/germinate-output/ubuntu.eoan/desktop-common
>
> It'd be desirable to fix this in `packageset-report' by allowing entire
> branches of the tree to be overridden. You'd write an exception like
>
>   gnome-shell   ubuntu  desktop
>
> and then everything that reflexively/transitively is pulled in to other
> seeds due to gnome-shell is treated as if it's in desktop. It'd be a bit
> of work to write this code, as this would require some deeper parsing of
> germinate's output, but it could be done.
>

Quite right on "deeper parsing of germinate's output". It seems like
it's also a little clunky, in that if you noticed a very leaf package
in the wrong set, it might not be the "key package" to transitively
pull in others. And then you would have to visually parse germinate's
output to figure out which is the real "key".

I wonder if by now the "kubuntu and ubuntu-desktop" share is still
relevant by now (since it's an official release, but not longer really
sponsored by us the same way it used to be). Treating kubuntu like any
other flavor other than ubuntu-desktop would also largely address the
issue, I think... I'm reasonably certain I had played with the script
enough to see that, I just didn't feel comfortable making this kind of
change without further discussion.

Regards,

Mathieu Trudel-Lapierre <mathieu.tl at gmail.com>
Freenode: cyphermox, Jabber: mathieu.tl at gmail.com
4096R/65B58DA1 818A D123 0992 275B 23C2  CF89 C67B B4D6 65B5 8DA1