+localpackagediffs should permit syncing from adjacent series

[Bryce Harrington]

https://launchpad.net/ubuntu/oneiric/+localpackagediffs will permit syncing from Debian Sid unstable. Occasionally Ubuntu maintainers will need to sync from Debian Sid experimental, so having an option to do this from +localpackagediffs would enable this workflow.

Debian is a rolling release, and sometimes will stage changes that might be more ambitious or risky in experimental for a period of time (~weeks). Ubuntu is punctuated by freezes and cadenced releases, so sometimes we need to pull in one of these packages early in order to get the proposed fix into our release. Or sometimes we know the change is good and want to pull it in early.

As examples, here are two reports we prepare in Ubuntu, roughly similar to +localpackagediffs, that we use to keep track of Debian experimental versions. The idea of this bug report is to gain similar support in LP, so these independent reports become less necessary (and more widely available across Ubuntu):

http://www.bryceharrington.org/X/Reports/ubuntu-x-swat/versions-current.html
http://people.canonical.com/~platform/desktop/versions.html

[Bryce Harrington (bryce)]

From: Julian Edwards
To: Bryce Harrington
Cc: <email address hidden>, Sebastien Bacher

On Thursday 16 June 2011 21:08:44 Bryce Harrington wrote:
> On Thu, Jun 16, 2011 at 03:23:57PM +0100, Julian Edwards wrote:
> > On Thursday 16 June 2011 14:08:14 Sebastien Bacher wrote:
> > > * is the current page only tracking Debian unstable? GNOME3 is in
> > > experimental still in Debian and for desktop work we are interested to
> > > track experimental and not unstable, is there any way to do that?
> >
> > Each series can only track one set of parent distros at once,
> > unfortunately. We did put in a way of changing to a different parent
> > when opening a new series, which will be useful for LTSes.
>
> The particular workflow Sebastien is referring to here is that
> frequently, on a case-by-case basis, we want to sync from Debian's
> experimental tree to pull in changes they're not yet ready to put into
> unstable but that we know we want in Ubuntu. (With Debian being more of
> a rolling release, and Ubuntu more puctuated with freezes and more
> tightly cadenced releases, this use case does crop up fairly regularly.)

Ah fair enough. We don't cater well for that case at all right now. We did
assume it would not crop up very often but it seems that was an incorrect
assumption. Where it does happen we figured that someone could just do a
regular upload so it wasn't a blocker, but I guess it'll get annoying.
Perhaps we'll fix this in a future iteration on the feature.

> I do notice this bit in the LEP, which suggests some thought has gone
> into this (or a similar?) situation:
>
> * Allow a derived distribution to have more than one parent
> + Post-initialisation, add more parents so that they appear in the
> list of differences

This is for the OEM case, where they have a crazy-ass hierarchy of parent
overlay distros! :)

[Julian Edwards (julian-edwards)]

With the current model, this is going to be very hard.

[Julian Edwards (julian-edwards)]

You can do this with the API, when we open it up fully (it's currently restricted to people doing QA testing). Doing it in the UI won't be as easy since the available syncs are driven by what's different to the defined parent series.