Lightdm core dump, only tty

[Sorry you can’t embed media][Sorry can’t embed links] << how am I supposed to share tty logs lol?

Hello,I think the root cause is the download and install of kernel 5.15 rc3. Otherwise I don’t really see the culprit.
How to avoid the segfault? (basic programming skills with arch install experience)
By the way this issue is hard to dignose, as no explicit logs can be found into dmesg and journalctl.

Try with a LTS( Long Term Support) kernel, either 5.10 or 5.4 to see if it makes any difference. RC3 is a release candidate and 5.15.2 is now in Unstable branch, so a good number of changes have occurred since rc3.

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Ok this is not a kernel issue, but a driver one.
I have 2 laptops with intel 8565U cpus.
On one I have installed in Manjaro Settings Manager:

  • Video-linux
  • Video-modetting
  • Video-vesa

On the other after installing the later 2, it has produced the segfault.
So I’m trying to find ways to recompile lightdm.
It seems that installing these packages created some sort of regression.

xorg log says
parse_vt_settings: cannot open /dev/tty0 (permission denied) but I’m not sure who comes first.

lightdm --test-mode --debug says

w failed to open ?/run/lightdm/root:0? permission denied
w could not enumerate user data error opening /var/lib/lightdm-data
process exited 1

EDIT started removing packages 1 by 1 and found that old thread /t/my-video-vesa-nightmare-solved/31505

Ctr-Alt F2 and log in
sudo mhwd -r pci video-vesa
Restart, and that's it.

So apparently video-vesa was the culprit.
(the purpose of installing drivers was because battery is bad on this laptop and video encoding is faulty with hardware decoding)

Please read: