Re: core-updates-frozen: Planning for the last world rebuild

[Thiago Jung Bauermann <bauermann@kolabnow.com>]

Hello Ludo,

Em terça-feira, 28 de setembro de 2021, às 08:57:45 -03, Ludovic Courtès 
escreveu:
> Hello Guix!
> 
> Wouldn’t it be nice to get ‘core-updates-frozen’ merged?  :-)
> 
> What about merging the patches blocked by
> <https://issues.guix.gnu.org/50358>?  We could even have them on a
> separate branch, have Cuirass build it, and merge it 24–36h later, at
> which point substitute coverage should be reasonably good.
> 
> I haven’t followed the new ports, POWER9 and RISC-V.  If there’s
> anything needed in this area, like localized toolchain changes, please
> send a heads-up!

There are two things I’m aware of for POWER9:

• diffutils test fix: https://issues.guix.gnu.org/50239
• gcc-5 build with GCC 10 fix: https://issues.guix.gnu.org/49896

In the case of diffutils, IMHO ideally we would apply the v2 patch there for 
the world rebuild, but as Ludo suggested it’s also possible to make the 
change only for powerpc64le-linux and avoid affecting other platforms.

In the case of gcc-5, it’s the same situation actually. But in addition to 
that, `guix refresh --list-dependent` says that modifying gcc-5 would only 
cause 32 dependent packages to be rebuilt so it’s not necessary to address 
it for the world rebuild.

> As I say every time someone proposes a new port, the main issue is not
> the port itself but maintaining it longer-term.  And here it’s not even
> clear to me what the status of POWER9 is on ‘core-updates-frozen’, so
> it’d be great to get feedback on this, ensure Cuirass builds it, and so
> on.

Yeah, the status of POWER9 on ‘core-updates-frozen’ is obfuscated by some 
build failures early in the dependency chain that were caused by QEMU bugs.
My impression is that the same is also true for aarch64-linux. For 
instance, QEMU can’t run libsigsegv’s testsuite (among other things), and 
that blocks a ton of stuff. Ditto for util-linux’s testsuite.

I was waiting for this world rebuild to happen to see the results in 
Cuirass now that powerpc64le-linux builds are only done on guixp9, but in 
hindsight it would have been better if I requested that those builds were 
restarted instead. Restarting this build should remove the main roadblock 
though:

https://ci.guix.gnu.org/build/703194/details

When that build is restarted and succeeds, does Cuirass also restart the 
builds that failed because they depended on it, or do we need to explicitly 
restart those as well?

What I can say is that IMHO POWER9 support isn’t too bad at least for the 
base packages given that I can build e.g., emacs (assuming that the patch 
for issue 50521 fixing a problem in gtk+-2 is applied), which depends on 
many base packages including X11 and GTK+.

-- 
Thanks,
Thiago