Bug#1109409: new occurrence for version 49-1.6

[Luc Maisonobe]

I think I encountered the same problem since this morning with gdm3
version 49-1.6, but am not sure it is really the same error.

When rebooting the commputer, the screen flashes a little but remain
black, without displaying the user selection widget, and it is
impossible to switch to a console screen using Ctrl-Alt-Fn. The only
thing that worked was rebooting using Ctrl-Alt-Suppr, and then
switching to recovery session.

It seems gdm was the culprit as journalctl showed this:

nov. 07 16:47:38 lehrin gdm-launch-environment][2449]: pam_unix(gdm-
launch-environment:session): session opened for user gdm-
greeter(uid=60578) by (uid=0)
nov. 07 16:47:38 lehrin gdm3[2442]: Gdm: GdmSession: no session desktop
files installed, aborting...
nov. 07 16:47:38 lehrin systemd[1]: gdm.service: Main process exited,
code=killed, status=5/TRAP
nov. 07 16:47:38 lehrin systemd[1]: gdm.service: Failed with result
'signal'.
nov. 07 16:47:38 lehrin systemd[1]: gdm.service: Triggering OnFailure=
dependencies.
nov. 07 16:47:39 lehrin systemd[1]: gdm.service: Scheduled restart job,
restart counter is at 2.
nov. 07 16:47:39 lehrin systemd[1]: Starting gdm.service - GNOME
Display Manager...
nov. 07 16:47:40 lehrin systemd[1]: Started gdm.service - GNOME Display
Manager.
nov. 07 16:47:40 lehrin gdm-launch-environment][2502]: pam_unix(gdm-
launch-environment:session): session opened for user gdm-
greeter(uid=60578) by (uid=0)
nov. 07 16:47:40 lehrin gdm3[2496]: Gdm: GdmSession: no session desktop
files installed, aborting...
nov. 07 16:47:40 lehrin systemd[1]: gdm.service: Main process exited,
code=killed, status=5/TRAP
nov. 07 16:47:40 lehrin systemd[1]: gdm.service: Failed with result
'signal'.
nov. 07 16:47:40 lehrin systemd[1]: gdm.service: Triggering OnFailure=
dependencies.
nov. 07 16:47:41 lehrin systemd[1]: gdm.service: Scheduled restart job,
restart counter is at 3.
nov. 07 16:47:41 lehrin systemd[1]: Starting gdm.service - GNOME
Display Manager...
nov. 07 16:47:41 lehrin systemd[1]: Started gdm.service - GNOME Display
Manager.
nov. 07 16:47:41 lehrin gdm-launch-environment][2527]: pam_unix(gdm-
launch-environment:session): session opened for user gdm-
greeter(uid=60578) by (uid=0)
nov. 07 16:47:41 lehrin gdm3[2521]: Gdm: GdmSession: no session desktop
files installed, aborting...
nov. 07 16:47:41 lehrin systemd[1]: gdm.service: Main process exited,
code=killed, status=5/TRAP
nov. 07 16:47:41 lehrin systemd[1]: gdm.service: Failed with result
'signal'.
nov. 07 16:47:41 lehrin systemd[1]: gdm.service: Triggering OnFailure=
dependencies.
nov. 07 16:47:42 lehrin systemd[1]: gdm.service: Scheduled restart job,
restart counter is at 4.
nov. 07 16:47:42 lehrin systemd[1]: Starting gdm.service - GNOME
Display Manager...
nov. 07 16:47:42 lehrin systemd[1]: Started gdm.service - GNOME Display
Manager.
nov. 07 16:47:42 lehrin gdm-launch-environment][2554]: pam_unix(gdm-
launch-environment:session): session opened for user gdm-
greeter(uid=60578) by (uid=0)
nov. 07 16:47:42 lehrin gdm3[2548]: Gdm: GdmSession: no session desktop
files installed, aborting...
nov. 07 16:47:42 lehrin systemd[1]: gdm.service: Main process exited,
code=killed, status=5/TRAP
nov. 07 16:47:42 lehrin systemd[1]: gdm.service: Failed with result
'signal'.
nov. 07 16:47:42 lehrin systemd[1]: gdm.service: Triggering OnFailure=
dependencies.
nov. 07 16:47:43 lehrin systemd[1]: gdm.service: Scheduled restart job,
restart counter is at 5.
nov. 07 16:47:43 lehrin systemd[1]: gdm.service: Start request repeated
too quickly.
nov. 07 16:47:43 lehrin systemd[1]: gdm.service: Failed with result
'signal'.
nov. 07 16:47:43 lehrin systemd[1]: Failed to start gdm.service - GNOME
Display Manager.
nov. 07 16:47:43 lehrin systemd[1]: gdm.service: Triggering OnFailure=
dependencies.



Searching for "GdmSession: no session desktop files installed" error, I
found some hints about gnome 49 dropping X support and
/usr/share/wayland-sessions vs /usr/share/xsessions, but on my
computer, both exist:

(lehrin) luc% ls -l /usr/share/wayland-sessions/
total 56
-rw-r--r-- 1 root root 8240 31 oct.  13:34 gnome-classic.desktop
-rw-r--r-- 1 root root 8364 31 oct.  13:34 gnome-classic-
wayland.desktop
-rw-r--r-- 1 root root 8014 31 oct.  14:23 gnome.desktop
-rw-r--r-- 1 root root 8570 31 oct.  14:23 gnome-wayland.desktop
-rw-r--r-- 1 root root 9175 22 août  17:07 xfce-wayland.desktop
(lehrin) luc% ls -l /usr/share/xsessions/
total 16
-rw-r--r-- 1 root root    86 21 juin   2024 lightdm-xsession.desktop
-rw-r--r-- 1 root root 10257 22 août  17:07 xfce.desktop
(lehrin) luc%

The only way I found to at least get an environment was to first
uncomment "WaylandEnable=false" in /etc/gdm3/daemon.conf, which at
least allowed to switch to a console, and then to install task-xfce-
desktop in order to avoid gdm. I tried using "dbus-run-session --
gnome-shell --display-server --wayland" as proposed above, but it
didn't work.

For now, gdm3 seems impossible to use on my computer.


best regards,
Luc