lightdm: WARNING: Failed to create /var/lib/gdm/.config/glib-2.0/settings: Permission denied

[pmenzel]

/var/log/lightdm/seat0-greeter.log contains:

[+0.01s] WARNING: Failed to create /var/lib/gdm/.config/glib-2.0/settings: Permission denied

No idea, why gdm is in that path name. (Because we use that existing user also for lightdm?)

Anyway, the directory above does not exist. Only:

$ sudo ls -l /var/lib/gdm/.config/dconf/user
-rw-r--r-- 1 gdm gdm 1755 Sep 30  2019 /var/lib/gdm/.config/dconf/user

The warning does not cause any visible problems though.