Mathieu Othacehe <othacehe@gnu.org> writes:

> Hello,
>
> I've observed a few Cuirass crashes the past days. The log looks like:
>
> --8<---------------cut here---------------start------------->8---
> 2020-09-11T12:55:35 next evaluation in 300 seconds
> GC Warning: Repeated allocation of very large block (appr. size 28766208):
>         May lead to memory leak and poor performance
> 2020-09-11T12:58:52 heap: 942.38 MiB; threads: 110; file descriptors: 257
> 2020-09-11T13:00:35 fetching input 'core-updates' of spec 'core-updates-core-updates'
> 2020-09-11T13:00:54 fetched input 'core-updates' of spec 'core-updates-core-updates' (commit "1bec03df9b60f156c657a64a323ef27f4ed14b44")
> 2020-09-11T13:00:54 fetching input 'guix' of spec 'guix-master'
> 2020-09-11T13:01:13 fetched input 'guix' of spec 'guix-master' (commit "7daa99e52d94e409f05a874813bdf739709807a2")
> 2020-09-11T13:01:13 evaluating spec 'guix-master'
> 2020-09-11T13:01:13 fetching input 'guix-modular' of spec 'guix-modular-master'
> 2020-09-11T13:01:17 fetched input 'guix-modular' of spec 'guix-modular-master' (commit "7daa99e52d94e409f05a874813bdf739709807a2")
> 2020-09-11T13:01:17 evaluating spec 'guix-modular-master'
> 2020-09-11T13:01:17 fetching input 'kernel-updates' of spec 'kernel-updates'
> 2020-09-11T13:01:21 fetched input 'kernel-updates' of spec 'kernel-updates' (commit "1de80be489e443e7c0d8c79ea84762e1706e81ff")
> 2020-09-11T13:01:21 fetching input 'staging' of spec 'staging-staging'
> 2020-09-11T13:01:24 fetched input 'staging' of spec 'staging-staging' (commit "de3c03a47160dec355d9b19ad5ca210d90c15fd7")
> 2020-09-11T13:01:24 fetching input 'version-1.0.1' of spec 'version-1.0.1'
> 2020-09-11T13:01:27 fetched input 'version-1.0.1' of spec 'version-1.0.1' (commit "58d7909c97c1ab2457faee1d7af925ee32ad15c2")
> 2020-09-11T13:01:27 fetching input 'version-1.1.0' of spec 'version-1.1.0'
> mmap(PROT_NONE) failed
> WARNING: (guile-user): imported module (fibers) overrides core binding `sleep'
> 2020-09-11T13:01:30 performing database optimizations
> --8<---------------cut here---------------end--------------->8---
>
> It looks like a memory allocation failed causing a Cuirass/Guile crash.

So, I've seen this before but in a slightly different context, [1]. To
summarise, with Guile built with libgc@8 the Guix Data Service couldn't
processes Guix revisions, because the code it had Guile built with
libgc@8 run caused it to consistently crash with this error. The
workaround was to add a Guile variant built with libgc@7 and use this
for the guix package [2].

1: http://issues.guix.info/40525
2: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=40684

I'm not quite sure what Guile process is crashing here, but switching to
use Guile built with libgc@7 might help.