On Samstag, 11. März 2023, 13:03:41 CET Alexander Puchmayr wrote: > Hi there, > > After having done a world update, neither sddm nor lightdm do start an > Xserver anymore. The X server itself runs fine, I can start it from the > console and I after setting DISPLAY properly can even start programs using > it, but the login managers do not start X for some reason. > > No hint so far in the logs, and no ideas where I should looking. > > The system is running inside a virtualbox VM, with Win10 as host operating > system. >
Its even getting more strange, the very same image copied from the windows laptop to a linux box and started with kvm/libvirt works fine, but in windows/ virtualbox it doesn't. Now I have two completely identical systems which only differn in the hypervisor they're started with, named "virtualbox" and "libvirt". On both systems, I start lightdm from the command line with -d option, and compare the results. Intrestingly the "libvirt" system writes "New seat added from logind: seat0", the "virtualbox" system does not, which seems to be the relevant difference (see log output below) Further, I found the following command in another forum: Gdbus introspect --system --dest org.freedesktop.login1 --object-path /org/ freedesktop/login1/seat/seat0 And the relevant difference here is in the org.freedesktop.login1.Seat properties section ... readonly b CanGraphical = false; ... on virtualbox. The same command on "libvirt" machine shows "true" here. So, what is required for a login seat to be treated as "graphical"? Thanks Alex [virtualbox] # lightdm -d [+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log [+0.00s] DEBUG: Starting Light Display Manager 1.32.0, UID=0 PID=867 [+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/ lightdm.conf.d [+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/ lightdm.conf.d [+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d [+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf [+0.00s] DEBUG: Registered seat module local [+0.00s] DEBUG: Registered seat module xremote [+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager [+0.01s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ?gio-vfs? [+0.01s] DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3) [+0.02s] DEBUG: Monitoring logind for seats [+0.02s] DEBUG: Acquired bus name org.freedesktop.DisplayManager [+0.02s] DEBUG: Could not run plymouth --ping: Failed to execute child process ?plymouth? (No such file or directory) [+0.02s] DEBUG: Loading users from org.freedesktop.Accounts [+0.02s] DEBUG: User /org/freedesktop/Accounts/User2001 added [+0.02s] DEBUG: User /org/freedesktop/Accounts/User1001 added [+0.09s] DEBUG: User /org/freedesktop/Accounts/User2002 added ...waiting for ctrl-C and no login screen ... [libvirt] # lightdm -d [+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log [+0.00s] DEBUG: Starting Light Display Manager 1.32.0, UID=0 PID=793 [+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/ lightdm.conf.d [+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/ lightdm.conf.d [+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d [+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf [+0.00s] DEBUG: Registered seat module local [+0.00s] DEBUG: Registered seat module xremote [+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager [+0.00s] DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3) [+0.00s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ?gio-vfs? [+0.01s] DEBUG: Monitoring logind for seats [+0.01s] DEBUG: New seat added from logind: seat0 [+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:* [+0.01s] DEBUG: Seat seat0 has property CanMultiSession=no [+0.01s] DEBUG: Seat seat0: Starting [+0.01s] DEBUG: Seat seat0: Creating greeter session [+0.01s] DEBUG: Seat seat0: Creating display server of type x [+0.01s] DEBUG: Could not run plymouth --ping: Failed to execute child process ?plymouth? (No such file or directory) [+0.01s] DEBUG: Using VT 7 [+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7 [+0.01s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log [+0.01s] DEBUG: XServer 0: Writing X server authority to /var/run/lightdm/ root/:0 [+0.01s] DEBUG: XServer 0: Launching X Server [+0.01s] DEBUG: Launching process 799: /usr/bin/X :0 -seat seat0 -auth /var/ run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch [+0.01s] DEBUG: XServer 0: Waiting for ready signal from X server :0 [+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager [+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/ DisplayManager/Seat0 [+0.01s] DEBUG: Loading users from org.freedesktop.Accounts [+0.01s] DEBUG: User /org/freedesktop/Accounts/User2001 added [+0.02s] DEBUG: User /org/freedesktop/Accounts/User1001 added [+0.18s] DEBUG: User /org/freedesktop/Accounts/User2002 added [+0.40s] DEBUG: Got signal 10 from process 799 [+0.40s] DEBUG: XServer 0: Got signal from X server :0 [+0.40s] DEBUG: XServer 0: Connecting to XServer :0 [+0.40s] DEBUG: Seat seat0: Display server ready, starting session authentication [+0.40s] DEBUG: Session pid=815: Started with service 'lightdm-greeter', username 'root' [+0.55s] DEBUG: Session pid=815: Authentication complete with return value 0: Success [+0.55s] DEBUG: Seat seat0: Session authenticated, running command [+0.55s] DEBUG: Session pid=815: Running command /usr/sbin/lightdm-gtk-greeter [+0.55s] DEBUG: Creating shared data directory /var/lib/lightdm-data/root [+0.55s] DEBUG: Session pid=815: Logging to /var/log/lightdm/seat0-greeter.log [+0.55s] DEBUG: Activating VT 7 [+0.81s] DEBUG: Greeter connected version=1.32.0 api=1 resettable=false [+1.40s] DEBUG: Greeter start authentication for alex [+1.40s] DEBUG: Session pid=855: Started with service 'lightdm', username 'alex' [+1.41s] DEBUG: Session pid=855: Got 1 message(s) from PAM [+1.41s] DEBUG: Prompt greeter with 1 message(s)