bug#41123: shepherd exits for no good reason

[Ludovic Courtès]

Hello,

I witnessed a case with Shepherd 0.8.0 on ‘core-updates’
(7b07852ddb334c92bcef69666f21c599f1f0fa79) where shepherd exited all by
itself, all of a sudden.  Here’s what /var/log/messages shows:

--8<---------------cut here---------------start------------->8---
May  7 09:36:23 localhost vmunix: [   20.316829] shepherd[1]: Service 
user-homes has been started.
May  7 09:36:23 localhost vmunix: [   21.319625] shepherd[1]: Service nscd has 
been started.
May  7 09:36:23 localhost vmunix: [   21.321029] shepherd[1]: Service 
guix-daemon has been started.

[…]

May  7 09:36:52 localhost shepherd[1]: Exiting shepherd... 
May  7 09:36:52 localhost shepherd[1]: Service xorg-server has been stopped. 
May  7 09:36:52 localhost shepherd[1]: Service console-font-tty2 has been 
stopped. 
May  7 09:36:52 localhost shepherd[1]: Service term-tty2 has been stopped. 
May  7 09:36:52 localhost shepherd[1]: Service upower-daemon has been stopped. 
May  7 09:36:52 localhost shepherd[1]: Service elogind has been stopped. 
May  7 09:36:52 localhost ntpd[482]: ntpd exiting on signal 15 (Terminated)
May  7 09:36:52 localhost syslogd: exiting on signal 15
--8<---------------cut here---------------end--------------->8---

The end result was a kernel panic with exitcode=0x100 (meaning exited
with 1).

It looks as though one had run ‘herd stop root’.

Ludo’.