[Releasing] rethinking the branching scheme / sha1 proposal

[Oswald Buddenhagen]

On Wed, Feb 19, 2014 at 03:13:01PM +0100, Simon Hausmann wrote:
> On Wednesday 19. February 2014 14.34.51 Frederik Gladhorn wrote:
> > This is independent of Ossi's proposal and tries to solve a different
> > problem.
> > 
> > One of the pain points in this release was the "which sha1 makes it in".
> > I'd like to propose defining this part as it hopefully solves quite some of
> > the issues we had.
> > 
> > So far the procedure is roughly: "whenever whichever merge passes CI around
> > the cut-off time is in".
> > 
> > I would like to propose instead that we define a certain time, let's say a
> > week, where maintainers pick which sha1 in this time frame should be the one
> > used for branching.
> > 
> > This means we get a defined sha1 that goes from
> >  dev->stable and stable->release
> > and no longer chase a moving target (some tip of the branch).
> > To not overly complicate things for most modules where little changes happen
> > the release team makes a decision.
> > In case of a change in the branching system this is still valid in that it
> > would define the branching point.
> 
> I fully support that and I think we should do this in any case. Module 
> maintainers - where present - "deliver" a base sha1 that forms the 
> stabilization branch for the next minor release. Whether that delivery happens 
> within a week or until a certain point in time and what happens afterwards we 
> need to discuss of course :)
> 
> One immediate advantage of this proposal is that we can keep "dev" always 
> open.
>
no, not really. the idea behind locking down the source branch is
raising awareness, not some technical limitation. picking a random sha1
from a few days ago would only make the problem worse: a contributor
would have no guarantee that a change that integrated before the
official deadline actually made it into the downmerge, and for qtbase
and other busy repos it would be completely impossible to coordinate
things to a degree which avoids that problem.
the immediate effect of that would be lots of cherry-picks, quite the
opposite of what the temporary lockdown tries to achieve.

so in summary, this seems to be counterproductive.