Cannot login to lightdm after upgrade to trusty

[Louis Bouchard]

Even after applying the update for lightdm in -proposed I still cannot login to lightdm after the upgrade.

/var/log/lightdm/lightdm.log provides the following :

[+11.69s] DEBUG: Session pid=1932: Prompt greeter with 1 message(s)
[+14.82s] DEBUG: User /org/freedesktop/Accounts/User1000 changed
[+17.48s] DEBUG: Session pid=1932: Continue authentication
[+17.51s] DEBUG: Session pid=2856: Authentication complete with return value 0: Success
[+17.51s] DEBUG: Session pid=1932: Authenticate result for user caribou: Success
[+17.51s] DEBUG: Session pid=1932: User caribou authorized
[+17.53s] DEBUG: Session pid=1932: Greeter requests session ubuntu
[+17.53s] DEBUG: Seat: Failed to find session configuration ubuntu
[+17.53s] DEBUG: Seat: Can't find session 'ubuntu'

Content of /var/log/lightdm will be attached to the bug

[Louis Bouchard (louis)]

Forgot to mention that I had seen the following bug but it doesn't seem to have anything to do with it :

https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1279428

The upgrade was from a clean install of Saucy to Trusty

[Sebastien Bacher (seb128)]

Thank you for your bug report. Do you have ubuntu-session installed? (if not, how did you dist-upgrade, that's a Depends of ubuntu-desktop which should be installed on any Ubuntu installation)

[Louis Bouchard (louis)]

Hi seb128,

Yes, I used dist-upgrade -d

Indeed, for some obscure reason, ubuntu-session got removed during the upgrade. Here is what it brought in :

Lecture des listes de paquets…
Construction de l'arbre des dépendances…
Lecture des informations d'état…
Les paquets suivants ont été installés automatiquement et ne sont plus nécessaires :
  libexpat1-dev libjson0:i386 libpython3-dev libpython3.3-dev libpython3.4-dev
  libtasn1-3:i386 libtommath0 linux-headers-3.11.0-14
  linux-headers-3.11.0-14-generic linux-image-3.11.0-14-generic
  linux-image-extra-3.11.0-14-generic linux-tools-3.11.0-14
  linux-tools-3.11.0-14-generic python3-dev python3.3-dev python3.4-dev
Veuillez utiliser « apt-get autoremove » pour les supprimer.
Les paquets supplémentaires suivants seront installés :
  compiz-core compiz-gnome compiz-plugins-default gsettings-ubuntu-schemas
  libcompizconfig0 libdecoration0 libglew1.10 libglewmx1.10 libnux-4.0-0
  libnux-4.0-common libprotobuf8 libtimezonemap1 libunity-control-center1
  libunity-core-6.0-9 libunity-protocol-private0 libunity9 ubuntu-settings
  unity unity-control-center unity-services unity-settings-daemon
Paquets suggérés :
  glew-utils
Les paquets suivants seront ENLEVÉS :
  libunity-core-6.0-8
Les NOUVEAUX paquets suivants seront installés :
  gsettings-ubuntu-schemas libglew1.10 libglewmx1.10 libprotobuf8
  libunity-control-center1 libunity-core-6.0-9 ubuntu-session
  unity-control-center unity-settings-daemon
Les paquets suivants seront mis à jour :
  compiz-core compiz-gnome compiz-plugins-default libcompizconfig0
  libdecoration0 libnux-4.0-0 libnux-4.0-common libtimezonemap1
  libunity-protocol-private0 libunity9 ubuntu-settings unity unity-services
13 mis à jour, 9 nouvellement installés, 1 à enlever et 1973 non mis à jour.
Il est nécessaire de prendre 810 ko/7 661 ko dans les archives.
Après cette opération, 10,8 Mo d'espace disque supplémentaires seront utilisés.
Souhaitez-vous continuer [O/n] ? Réception de : 1 http://archive.ubuntu.com/ubuntu/ trusty/main libunity-control-center1 amd64 14.04.3+14.04.20140305.1-0ubuntu1 [81,0 kB]
Réception de : 2 http://archive.ubuntu.com/ubuntu/ trusty/main ubuntu-settings all 14.04.5 [4 422 B]
Réception de : 3 http://archive.ubuntu.com/ubuntu/ trusty/main unity-control-center amd64 14.04.3+14.04.20140305.1-0ubuntu1 [725 kB]
Committing to: /etc/
modified apt/sources.list
modified cups/printers.conf
Committed revision 296.
810 ko réceptionnés en 0s (934 ko/s)
Sélection du paquet libprotobuf8:amd64 précédemment désélectionné.
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[Sebastien Bacher (seb128)]

did you have ubuntu-desktop installed before the upgrade? when you say "dist-upgrade -d" is that apt (command line) or the dist-upgrader

[Louis Bouchard (louis)]

yeah, it was a clean install from saucy.

Going back in the log, I did

 $ do-release-upgrade -d

At the end, there were a few broken installs that needed to be fixed with apt-get -f install

I must be honest, it's the first time I upgrade to the dev release, I may have totally screwed things up !

[Tim (thelfensdrfer)]

I have the same problem. did also upgrade with

sudo apt-get update
sudo apt-get dist-upgrade
sudo update-manager -d

but had no error during or after the upgrade process. The log output is the same:

DEBUG: Seat: Failed to find session configuration ubuntu
DEBUG: Seat: Can't find session 'ubuntu'

There is an answer on askubuntu (http://askubuntu.com/a/439472/178883) but it did not help because "gnome" is replaced by "ubuntu" after every restart.

[Tim (thelfensdrfer)]

Problem solved after installing "ubuntu-session" via ssh.

[BlessJah (blessjah)]

Also had this problem, fixed after dist-upgrade and reinstalling ubuntu-desktop.

[Sergey Zolotarev (szx)]

I fixed this by installing unity-greeter and manually editing /etc/lightdm/lighdm.conf (greeter-session was empty for some reason, I had to set it to "unity-greeter").