Subject: bug#76315: System does not boot after switching to system-log service

From: Ludovic Courtès <[email-masked]>
Date: Wed, 19 Feb 2025 22:04:20 +0100

Hey Tomas,

Ludovic Courtès <[email-masked]> skribis:

> I tried the config file you gave with:
>
>   ./pre-inst-env guix system vm /tmp/config.scm
>
> and it hangs, to my surprise (I’ve been using ‘system-log’ on my laptop
> since June, and “make check-system TESTS=basic” & co. pass).

After spending hours on this and fixing improbable issues in the
Shepherd (will push shortly), I found that the root of the problem is
exactly what I feared and which led to the patches at
<https://issues.guix.gnu.org/76262>.

Namely, ‘dhcp-client-service-type’ calls ‘waitpid’; that call competes
with the one done by shepherd’s SIGCHLD handler and, if you’re unlucky,
it loses the race and waits forever.  (I’m using
‘network-manager-service-type’ on my laptop, which is why I did not
stumble upon this bug.)

Could you try your config with the patch at
<https://issues.guix.gnu.org/76262#2>, at least in a VM and ideally on
the metal?

Thanks in advance,
Ludo’.