Arch Linux

youngdm

Member

Registered: 2013-08-02

Posts: 20

Lightdm background image overdrawn with white foreground at boot

I have Arch 3.17.4-1 installed on a Macbook Pro 7,1 to dual boot with OSX (using the Nouveau video drivers). Grub boots from a separate blessed partition as the default. I use Xfce4 4.10 as the desktop. The installation has been updated weekly over the last 18 months or so. I always used to start Xfce4 using 'startx' but have recently needed to configure the system for multiple users and so after a look at Lxdm decided to use lightdm with lightdm-gtk2-greeter. Lightdm is version 1.12.2-1 from community.

Everything nearly works as it should. If I set the background of lightdm as as plain colour all works fine. However there is some odd beahviour if I set the background to an image file. The image files have rw permissions set for u,g+o and are located in /usr/share/pixmaps/. I can set an avatar for the login panel using accounts service as described in the Arch Wiki. When I boot the pc, I get a white foreground around the login panel instead of the background image. I initially thought this was because the background had failed to display. However, if I switch to a second getty and then back to the greeter the background is displayed correctly. Also, if I login and then logout, the background is displayed correctly and; if I reboot, rather than shutdown and restart, the background displays correctly. The behaviour is the same if I use the lightdm-gtk3-greeter.

Obviously I can run the greeter with just a solid colour background (or run lxdm which doesn't suffer the same problem) but I've been fiddling around with this on and off for a few days and so would like to resolve the issue if possible.

The only issue I can see in lightdm.log is:

[+0.45s] DEBUG: Could not run plymouth --ping: Failed to execute child process "plymouth" (No such file or directory)

Xorg.0.log gives this error when using both Lightdm or Lxdm

(EE) systemd-logind: failed to get session: PID 385 does not belong to any known session

PID TTY      STAT   TIME COMMAND
 385 tty1     Ss+    1:30 /usr/bin/Xorg.bin :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt1 -novt

I think these are the relevant details from systemd journal

systemd[1]: Starting Session c1 of user lightdm.
systemd-logind[359]: New session c1 of user lightdm.
systemd[1]: Started Session c1 of user lightdm.
systemd[1]: Starting Multi-User System.
systemd[1]: Reached target Multi-User System.
systemd[1]: Starting Graphical Interface.
systemd[1]: Reached target Graphical Interface.
systemd[1]: Starting Session c2 of user youngdm.
systemd-logind[359]: New session c2 of user youngdm.
systemd[1]: Started Session c2 of user youngdm.

Any thoughts about where I should look?