bug#59343: GDM hangs at login screen

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hi,

Since moving from my system generation 441 to 442, GDM gets stuck, where
no input can be provided via the keyboard and the mouse moves the
pointer but clicking doesn't cause the GDM buttons to be activated,
preventing login.

--8<---------------cut here---------------start------------->8---
menuentry "GNU with Linux-Libre 6.0.8 (#442, 2022-11-16 17:56)" {

  linux /gnu/store/a038dw3aa286pblg2w6lavj3afn150h2-linux-libre-6.0.8/bzImage root=2e97fbbd-fa4e-4858-948b-b3a89278a39b gnu.system=/var/guix/profiles/system-442-link gnu.load=/var/guix/profiles/system-442-link/bo
ot quiet modprobe.blacklist=rtl8187,snd_hda_intel
  initrd /gnu/store/kqz5kr9hrm0w7yhv4ddswvl456mk4466-raw-initrd/initrd.cpio.gz
}
menuentry "GNU with Linux-Libre 5.19.17 (#441, 2022-10-28 21:30)" {

  linux /gnu/store/z2fcr22r752g2smwhy677bqfqmr8vjk0-linux-libre-5.19.17/bzImage root=2e97fbbd-fa4e-4858-948b-b3a89278a39b gnu.system=/var/guix/profiles/system-441-link gnu.load=/var/guix/profiles/system-441-link/
boot quiet modprobe.blacklist=rtl8187,snd_hda_intel
  initrd /gnu/store/g1hq3k3ralsah3xn1yvcfql9jvw7vhiy-raw-initrd/initrd.cpio.gz
}
--8<---------------cut here---------------end--------------->8---

I've done many tests but couldn't isolate the problem.  What I know is
that:

1. It's doesn't seem related to the kernel; I was able to reproduce the
issue with 5.15 (although I think after a very long while it eventually
unfroze).

2. The logs don't contain any clue (I've diffed /var/log/gdm/* between a
working and not working boot), and looked at the Xorg log, which also
appeared normal.

3. I cannot reproduce the problem in a VM.  A different but similar
system definition on a 2nd machine (X200 laptop) doesn't exhibit the
issue either.

I'm out of ideas, but I'm creating this issue in the rare event someone
would be able to reproduce it.  I'll try it again when we move to GDM
43.

-- 
Thanks,
Maxim