I recently migrated my linux box from bare metal hardware to a VMware virtual machine. At the same time, I upgraded from Debian squeeze to Debian Wheezy (testing).
After the dust had settled, one nagging problem keep recurring. Every time I did an aptitude update or aptitude install, after everything successfully ran, I would get this error message:
Error: GDBus.Error:org.freedesktop.DBus.Error.Spawn.ExecFailed: Failed to execute program /usr/lib/dbus-1.0/dbus-daemon-launch-helper: Success
The cause of this proved quite difficult to track down. Eventually a Gentoo forum post led me to the solution. It seems that somewhere along the line, dbus-daemon-launch-helper has ended up with the wrong permissions. Change its permissions to be world executable.
chmod o+x /usr/lib/dbus-1.0/dbus-daemon-launch-helper