[Pkg-xfce-devel] Bug#728361: xfce4: Nor working restart/shutdown buttons

[Jens Arnold]

I have been observing this problem on several machines too - disabled 
restart/ shutdown/ standby/ suspend buttons in xfce4 after upgrading 
lightdm to 1.8.2. When that happened, trying to start programs using 
pkexec from the GUI also stopped working. Subsequent updates to lightdm 
(namely 1.8.3 and 1.8.5) didn't fix the problem. On some of the machines 
I am maintaining, lightdm and xfce4 kept working properly - with the 
same versions that caused problems on the others.

Following this thread I verified the various things suggested, and noted 
that ck-list-sessions was unable to find the correct X session.

Today I digged further, and found the difference between the working 
machines and the non-working ones. The non-working ones had an extra 
entry in /etc/pam.d/common-session:

session optional     pam_systemd.so

This entry gets placed there by the package libpam-systemd. Removing 
this entry fixed the problem here. The working machines didn't have 
libpam-systemd installed, so I uninstalled it from all of them.
-- 
Mit freundlichen Grüßen / Best Regards

Jens Arnold