I have found the solution. As it turned out, the conflicting package was xserver-xorg-video-all. After deinstalling it, the upgrade went through. Maybe this can be fixed generally as only a close look into the debug files gives hints.
I have found the solution. As it turned out, the conflicting package was xserver- xorg-video- all. After deinstalling it, the upgrade went through. Maybe this can be fixed generally as only a close look into the debug files gives hints.