bug#38232: Cuirass: Some builds fail although their log file ends with 'build-succeeded'

[Mathieu Othacehe <m.othacehe@gmail.com>]

> It seems to be also an issue for evaluations that look successful but
> are reported as failed, see here:

Looking at those evaluation logs, I think there is yet another issue. On
core-updates:

* Evaluation 8747 fails because it cannot build curl
(https://ci.guix.gnu.org/eval/8748/log/raw).

* Next evaluation 8762, considers curl build as previously failed:
--8<---------------cut here---------------start------------->8---
Computing Guix derivation for 'x86_64-linux'...  builder for `/gnu/store/1510sg9h2ivq4841gqm9dhmq5l50a52b-curl-7.66.0' failed previously (cached)
@ build-failed /gnu/store/pqfnxfk5xx0ngc32wlq87vhchh80mnkw-curl-7.66.0.drv - cached--8<---------------cut here---------------end--------------->8---
and fails immediately.

The curl build problem (at 8747 evaluation) seems related to some failed
test case (1242) that I cannot reproduce locally.

Will all future evaluations re-use this cache and also fail immediately?
If yes, how can we unblock the situation?

Mathieu