Comment 6 for bug 1431714

I have exactly the same problem, here some output of "sudo apt-get -o Debug::pkgProblemResolver=yes dist-upgrade" if it can help...

Lecture des listes de paquets... Fait
Construction de l'arbre des dépendances
Lecture des informations d'état... Fait
Calcul de la mise à jour... Starting pkgProblemResolver with broken count: 3
Starting 2 pkgProblemResolver with broken count: 3
Investigating (0) libgl1-mesa-dri-lts-utopic [ amd64 ] < 10.3.2-0ubuntu1~trusty2 > ( libs )
Broken libgl1-mesa-dri-lts-utopic:amd64 Est en conflit avec on libgl1-mesa-dri [ amd64 ] < none -> 10.6.0~git20150616+10.6.5d327b37-0ubuntu0ricotz~trusty > ( libs )
  Considering libgl1-mesa-dri:amd64 5 as a solution to libgl1-mesa-dri-lts-utopic:amd64 14
  Added libgl1-mesa-dri:amd64 to the remove list
  Conflicts//Breaks against version 10.1.3-0ubuntu0.4 for libgl1-mesa-dri but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libgl1-mesa-dri but that is not InstVer, ignoring
  Fixing libgl1-mesa-dri-lts-utopic:amd64 via keep of libgl1-mesa-dri:amd64
Investigating (0) libgbm1 [ amd64 ] < 10.1.3-0ubuntu0.4 -> 10.6.0~git20150616+10.6.5d327b37-0ubuntu0ricotz~trusty > ( libs )
Broken libgbm1:amd64 Dépend on libgl1-mesa-dri [ amd64 ] < none -> 10.6.0~git20150616+10.6.5d327b37-0ubuntu0ricotz~trusty > ( libs ) (= 10.6.0~git20150616+10.6.5d327b37-0ubuntu0ricotz~trusty)
  Considering libgl1-mesa-dri:amd64 5 as a solution to libgbm1:amd64 0
  Holding Back libgbm1:amd64 rather than change libgl1-mesa-dri:amd64
 Try to Re-Instate (1) libgbm1:amd64
Done
Fait
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
Les paquets suivants ont été conservés :
  libgbm1
0 mis à jour, 0 nouvellement installés, 0 à enlever et 1 non mis à jour.