LightDM Failed to use bus name org.freedesktop.DisplayManager

Hello everyone! First time here, I am relatively new to Linux and I need your help.
I am currently running Manjaro KDE on a Surface pro 3 (Intel i7 with onboard graphics) and my clean install is barely a few days old.
I've been trying to get my device as touch-friendly as possible, which is why I have been trying to get LightDM running to use a virtual keyboard in my login screen. The current default dm is sddm.
However, following steps from arch wiki and manjaro wiki did not work for me. After being overly excited and disabling sddm before rebooting I had to go thorugh tty and all that fun to get my desktop environment back. I've tried both the KDE greeter and the gtk greeter. Whenever I run lightdm in test mode via

lightdm --test-mode

I get following output, although lightdm tells me to test without root:

code** (lightdm:3851): WARNING **: Error reading existing Xauthority: Failed to open file '/run/lightdm/root/:0': Permission denied

** (lightdm:3851): WARNING **: XServer 0: Failed to write authority: Failed to open X authority /run/lightdm/root/:0: Permission denied

** (lightdm:3851): WARNING **: Could not enumerate user data directory /var/lib/lightdm-data: Error opening directory '/var/lib/lightdm-data': Permission denied[/code]
Alright, looks to me like I need root. Running

sudo lightdm --test-mode --debug

however gives me following errors:

[+0.00s] DEBUG: Seat seat0: Creating greeter session
[+0.00s] 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 /run/lightdm/root/:0
[+0.01s] DEBUG: XServer 0: Launching X Server
[+0.01s] DEBUG: Launching process 3977: /usr/bin/Xephyr :0 -seat seat0 -auth /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/User1000 added
Failed to use bus name org.freedesktop.DisplayManager, do you have appropriate permissions?[/code]
Whatever I do, whatever I try, the test won't work and the output won't change. After searching the internet for 2 days trying to apply given solutions I've ended up here. All I need is a reliable virtual touch keyboard in login screen...

Any suggestion, no matter how dumb it might sound, is appreciated. Thank you.

https://bugzilla.redhat.com/show_bug.cgi?id=1428379
In particular, comments #7 and #8 in that bug report explain why this is happening and what's the workaround.

Thanks for the hint!

I've added the file /etc/systemd/system/lightdm.service.d/fixes.conf with content [code][Unit]
Wants=dbus.socket user.slice
After=dbus.socket user.slice

[Service]

Trying to explicitly declare Type=dbus as original lightdm.service has

BusName=org.freedesktop.DisplayManager which sets Type=dbus anyway acc. to

https://www.freedesktop.org/software/systemd/man/systemd.service.html

Type=dbus
RestartSec=10s
ExecStartPre=/bin/sleep 5[/code]

But all that I get is a longer debug output, leading to the very same problem:

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log [+0.00s] DEBUG: Starting Light Display Manager 1.22.0, UID=0 PID=1017 [+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: Using Xephyr for X servers [+0.00s] DEBUG: Registered seat module local [+0.00s] DEBUG: Registered seat module xremote [+0.00s] DEBUG: Registered seat module unity [+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager [+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: 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 /run/lightdm/root/:0 [+0.01s] DEBUG: XServer 0: Launching X Server [+0.01s] DEBUG: Launching process 1023: /usr/bin/Xephyr :0 -seat seat0 -auth /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/User1000 added Failed to use bus name org.freedesktop.DisplayManager, do you have appropriate permissions?

These are the contents of the log it created:

_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed _XSERVTransMakeAllCOTSServerListeners: server already running (EE) Fatal server error: (EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE)

Of course an X-server with sddm is already running, which is why I'm launching lightDM in testing mode.
What am I missing? Something with permissions? Or should I just disable the sddm service, enable lightdm and try to reboot?

Yes, disable sddm, enable lightdm and reboot.

1 Like

Thank you, it actually works! (most of the time and as long as I don't try to launch wayland). Thanks

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.

Forum kindly sponsored by