bug#37423: Changing the login service from GDM to SLiM and then back to GDM causes a really bad loop

[Jan]

Hi.

Changing the login service from GDM to SLiM and then back to GDM makes
GDM to loop like this:
"New session c1 of user gdm."
"Removed session c1."
"New session c2 of user gdm."
"Removed session c2."
...

And it continues like this to relatively high numbers like c167. Didn't
check how far it could go, but that's not important anyway.
Reverting to the previous definition of the system by using 
"guix system switch-generation" or using grub menu entries doesn't help,
changing /etc/config.scm back to the default gdm configuration and
running 
"guix system reconfigure" doesn't help either.

There's also one strange thing that have happened before rebooting -
when logging off, SLiM was running in a loop too - I couldn't turn off
the computer using it, I had to switch to another tty and run "shutdown"
manualy.

But reverting to a configuration with SLiM works - I can use the system
with it, but can't with GDM anymore.

---
Jan Wielkiewicz