After some trials and errors, I found the culprit. The is only ONE package missing to open the session normally :
gsettings-ubuntu-schemas
So the conclusion is : if it is needed to properly open an X session then it SHOULD be a true dependency from another package, not just a recommended package.
Currently in artful gsettings-ubuntu-schemas is a dependency of the following packages:
In this list no package is installed except ubuntu-desktop, and it is the only package in this list that set gsettings-ubuntu-schemas as a recommended packages.
After some trials and errors, I found the culprit. The is only ONE package missing to open the session normally :
gsettings- ubuntu- schemas
So the conclusion is : if it is needed to properly open an X session then it SHOULD be a true dependency from another package, not just a recommended package.
Currently in artful gsettings- ubuntu- schemas is a dependency of the following packages:
$ apt-cache rdepends gsettings- ubuntu- schemas ubuntu- schemas settings- daemon control- center datetime ubuntu- touch-schemas
gsettings-
Reverse Depends:
unity
unity-
unity-
indicator-sound
indicator-
gsettings-
ubuntu-desktop
In this list no package is installed except ubuntu-desktop, and it is the only package in this list that set gsettings- ubuntu- schemas as a recommended packages.
So TMHO, gsettings- ubuntu- schemas SHOULD BE