bug#43334: Cuirass crashes

[Mathieu Othacehe]

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.

Thanks,

Mathieu