Bug#767388: gdm3 fails to discover kdm at install.

[r.ductor at gmail.com]

Dear maintainers

The upgrade to the most updated versions did not change the issue. My current conjecture  (I'm a newbie of systemd) is that there is an install problem. kdm.service seems built up in some dynamical way and gdm3 fails to discover it and to accept that kdm is the chosen service. The consequences that x-display-manager.target requires both kdm.service and gdm.service, which generates the failure of the assertion in gdm.service 

Thanks for your time
ric

MORE info:

* I've upgraded to most recent versions

gdm3 3.14.1-1
kdm 4:4.11.13-1

* During install ( aptitude full-upgrade I get )

Setting up gdm3 (3.14.0-1) ...
WARNING: /lib/systemd/system/kdm.service is the selected default display manager but does not exist
Warning: Unit file of gdm3.service changed on disk, 'systemctl daemon-reload' recommended.
Job for gdm.service failed. See 'systemctl status gdm.service' and 'journalctl -xn' for details.
invoke-rc.d: initscript gdm3, action "reload" failed.
..
Setting up kdm (4:4.11.13-1) ...


* After reboot (and logging in with kdm) same systemctl status:

# systemctl status gdm.service    
● gdm.service - GNOME Display Manager
   Loaded: loaded (/lib/systemd/system/gdm.service; static)
   Active: failed (Result: start-limit) since Fri 2014-10-31 10:17:47 CET; 7min ago
  Process: 1145 ExecStartPre=/bin/sh -c [ "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/sbin/gdm3" ] (code=exited, status=1/FAILURE)

Oct 31 10:17:45 IPhT-IA-004976 systemd[1]: Failed to start GNOME Display Manager.
Oct 31 10:17:45 IPhT-IA-004976 systemd[1]: Unit gdm.service entered failed state.
Oct 31 10:17:47 IPhT-IA-004976 systemd[1]: gdm.service start request repeated too quickly, refusing to start.
Oct 31 10:17:47 IPhT-IA-004976 systemd[1]: Failed to start GNOME Display Manager.
Oct 31 10:17:47 IPhT-IA-004976 systemd[1]: Unit gdm.service entered failed state.

Warning: Unit file changed on disk, 'systemctl daemon-reload' recommended.

# systemctl status kdm.service 
● kdm.service - LSB: X display manager for KDE
   Loaded: loaded (/etc/init.d/kdm)
  Drop-In: /run/systemd/generator/kdm.service.d
           └─50-kdm-$x-display-manager.conf
   Active: active (running) since Fri 2014-10-31 10:17:41 CET; 4min 50s ago
  Process: 1039 ExecStart=/etc/init.d/kdm start (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/kdm.service
           ├─1057 /usr/bin/kdm -config /var/run/kdm/kdmrc
           └─1062 /usr/bin/X :0 vt7 -br -nolisten tcp -auth /var/run/xauth/A:0-W6NTPb

Oct 31 10:17:41 IPhT-IA-004976 kdm[1039]: Starting K Display Manager: kdm.
Oct 31 10:17:46 IPhT-IA-004976 kdm_greet[1079]: Cannot load /usr/share/kde4/apps/kdm/faces/.default.face: No such file or directory
Oct 31 10:18:14 IPhT-IA-004976 kdm[1072]: :0[1072]: pam_unix(kdm:auth): authentication failure; logname= uid=0 euid=0 tty=:0 ...r=guida
Oct 31 10:18:26 IPhT-IA-004976 kdm[1072]: :0[1072]: pam_unix(kdm:session): session opened for user guida by (uid=0)
Hint: Some lines were ellipsized, use -l to show in full.
# systemctl is-enabled kdm.service
Failed to get unit file state for kdm.service: No such file or directory

* Then I tried to inquire who loads whom:

# systemctl show -p "WantedBy" gdm.service  
WantedBy=
# systemctl show -p "RequiredBy" gdm.service      
RequiredBy=x-display-manager.target
# systemctl show -p "WantedBy" kdm.service  
WantedBy=graphical.target multi-user.target
# systemctl show -p "RequiredBy" kdm.service      
RequiredBy=x-display-manager.target
# systemctl status x-display-manager.target
● x-display-manager.target - X11 Display Manager
   Loaded: loaded (/etc/insserv.conf.d/kdm; static)
  Drop-In: /run/systemd/generator/x-display-manager.target.d
           └─50-hard-dependency-gdm3-$x-display-manager.conf, 50-hard-dependency-kdm-$x-display-manager.conf
   Active: active since Fri 2014-10-31 10:17:47 CET; 13min ago

* As a further test I tried to reconfigure gdm3 getting the same error

# dpkg-reconfigure gdm3 
WARNING: /lib/systemd/system/kdm.service is the selected default display manager but does not exist
Warning: Unit file of gdm3.service changed on disk, 'systemctl daemon-reload' recommended.
Job for gdm.service failed. See 'systemctl status gdm.service' and 'journalctl -xn' for details.
invoke-rc.d: initscript gdm3, action "reload" failed.
# cat /etc/X11/default-display-manager
/usr/bin/kdm