On a machine where I installed the XFCE spin, gdm autologin to a user
account is not working. I copied custom.conf from a different Gnome-based
machine where autologin is working, but on the one with the XFCE spin, the
autologin fails, and kick me back to a regular user login prompt, in gdm.
I can only think of three possibilities: something in /etc/pam.d/gdm-
autologin is barfing; or the PAM stuff runs fine, but leaves the user
session in a state that can't start XFCE, for some reason; or gdm's
autologin is hardcoded for the Gnome shell in some way, which won't work,
obviously, in the XFCE spin.
If you have gdm autologin working in the XFCE spin, I'd like to compare
notes.
I have selinux turned off. The only other factor I can think of that might
be relevant is that the XFCE spin machine has everything mounted noatime.