Picuntu 0.9 RC3 crash in XFCE (dbus)

Symptoms:

If any of these happen to you:

- Ubuntu Software Center issues a crash report when clicking an app's "Install" button (plus install doesn't start)

- Settings Manager: crashes and no window opens when clicking over any of Settings icons (like "Language Support")

Spotting the problem:

Open a terminal and enter:

sudo cat /var/log/syslog

If the last lines report issues like:

Activated service '....' failed: Failed to execute program /usr/lib/dbus-1.0/dbus-dameon-launch-helper success

Then there likely are permission problems with the above mentioned dbus daemon helper. Now enter:

cd /usr/lib/dbus-1.0/

ll

If everything were right you would get the following result:

-rwsr-xr-- 1 root messagebus 170348 Oct 3 23:18 dbus-daemon-launch-helper*

Date/time/size are unimportant. The permissions (-rwsr-xr--) and group ownership (messagebus) is what matters.

In my case I got the following result:

-rwsr-xr-- 1 root ssh 170348 Oct 3 23:18 dbus-daemon-launch-helper*

 So the group ownership is dead wrong, preventing the file from being run properly.

Fix Procedure:

Enter the following commands:

sudo chgrp messagebus dbus-daemon-launch-helper

Now, doing "ll", you may find that the group is fine, but the permissions have changed. To correct them, type:

sudo chmod u=rwxs,g=rx,o=r dbus-daemon-launch-helper

Check that "ll" returns the above expected result and, then, safely restart the stick (you don't want to corrupt the SD flash card!):

sudo shutdown -P now 

Once you get back into Picuntu, the problem should be fixed.



References:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=659953