Subject: [bug#69414] Emacs and Gnome branches are merged now

From: Christopher Baines <[email-masked]>
Date: Sat, 30 Mar 2024 14:20:38 +0000

Liliana Marie Prikler <[email-masked]> writes:

> I've now pushed the merge commits for both emacs-team and gnome-team.

Thank you to everyone involved in getting these changes through :D

> If you have a weak machine, PLEASE DO NOT PULL IMMEDIATELY AND WAIT FOR
> CI TO CATCH UP!  Despite efforts to prebuild things on the respective
> branches, the merge commit carries with it a rebuild of the most nasty
> package to have to compile locally.

I've had a look in to this as it would be good to work out how this
happened, and how we might avoid it in the future.

I had a look at QEMU and gtk, diffing the derivations from the
gnome-team branch prior to the merge to the master branch after the
merge.

QEMU was affected by the usbutils update in
855fecf00f7df8bf878a8ecd47800ea9bdfebea5, which was pushed to master on
the 26th of March. For gtk, it was affected by the psmisc update in
a2d82fbec4254cf6127b15aa3e827d22da235c30 which was pushed at the same
time.

I think the last merge of master in to gnome-team was pushed on the 20th
of March, with the merge of gnome-team in to master being pushed today
on the 30th.

Looking at those dates, it seems like bringing changes from master in to
branches more frequently, or at least just before considering whether
it's ready to merge (and merging if it is) would help to avoid this. 10
days is a long window in which changes can be pushed to master. QA is
meant to pick up when a branch has diverged from master, but the
mechanism is crude and the threshold it was using was very high. I've
now reduced it [1] so QA might warn in the future about this situation.

1: https://git.savannah.gnu.org/cgit/guix/qa-frontpage.git/commit/?id=b1d7225636d7c1946f4718d6441a621d51f8cd6a

While I don't think it's directly relevant, I think it's worth noting
that both changes mentioned above (usbutils and psmisc), we didn't
follow our own guidance on managing patches. psmisc affects more than
300 dependent packages, and while I think that's less of an issue if
changes go through QA, I don't think either of these changes did.