Got working gdm 3.8.4-3 for me. The issue was the enabled autologin.
/etc/gdm3/daemon.conf: [daemon] # AutomaticLoginEnable = false # AutomaticLogin = Which seams to use su in background and run into the runtime_path bug. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

