According with your "loginctl seat-status seat0" outputs, it seems your live session lacks framebuffer devices (/dev/fb*) for VirtualBox/VMware. Just for comparison, my Lubuntu system installed in a VirtualBox VM does have a framebuffer device, so I suspect some needed kernel module for providing framebuffer devices in VirtualBox is missing/not loaded for a live session.
Anyway, this problem with CanGraphical=no seat0 are strictly related to the lack of framebuffer devices in the system, so it can't be related to xserver-xorg-video-* drivers. @robert-ancell, in fact, CanGraphical property check was never implemented in GDM, although there's a 2-years-old open bug by Lennart: https://bugzilla.gnome.org/show_bug.cgi?id=678535 I will write to systemd-devel mailing list asking for suggestions. In the meanwhile, it's better to make CanGraphical check in lightdm optional (and disabled by default until we can address these issues with missing framebuffer devices). ** Bug watch added: GNOME Bug Tracker #678535 https://bugzilla.gnome.org/show_bug.cgi?id=678535 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1365336 Title: Lightdm update=No desktop Status in “fglrx-installer” package in Ubuntu: In Progress Status in “fglrx-installer-updates” package in Ubuntu: In Progress Status in “lightdm” package in Ubuntu: Confirmed Status in “nvidia-graphics-drivers-304” package in Ubuntu: Fix Released Status in “nvidia-graphics-drivers-331” package in Ubuntu: Fix Released Status in “nvidia-graphics-drivers-331-updates” package in Ubuntu: Fix Released Status in “xserver-xorg-video-vesa” package in Ubuntu: Confirmed Status in “xserver-xorg-video-vmware” package in Ubuntu: Confirmed Bug description: Update to lightdm from 1.11.7-0ubuntu1 to 1.11.8-0ubuntu1 leaves me with no desktop on normal boot. Machine boots directly to tty1. Logged in at tty1 and then startx leads to a desktop that requires password to start properly and with themes unapplied. Password required to reboot machine. ProblemType: Bug DistroRelease: Ubuntu 14.10 Package: lightdm 1.11.8-0ubuntu1 ProcVersionSignature: Ubuntu 3.16.0-12.18-generic 3.16.1 Uname: Linux 3.16.0-12-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.14.7-0ubuntu1 Architecture: amd64 CurrentDesktop: XFCE Date: Thu Sep 4 08:20:14 2014 InstallationDate: Installed on 2014-07-17 (48 days ago) InstallationMedia: Xubuntu 14.10 "Utopic Unicorn" - Alpha amd64 (20140717) SourcePackage: lightdm UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fglrx-installer/+bug/1365336/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
