Comment 36 for bug 1161371

[ 7.012094] init: gdm main process (1254) killed by TERM signal

Same bug as the lightdm race, but with gdm instead?

Looking at upstart files, it looks like plymouth-stop is running in parallel with gdm, causing the race you see above..

The dependencies in plymouth-stop:

start on (starting gdm
          or starting kdm
          or starting xdm
          or starting lxdm
          or starting lightdm
          or starting uxlaunch
          or starting ubiquity
          or starting oem-config
          or stopped rc RUNLEVEL=[2345]
          or starting rcS
          or starting mountall-shell)

makes me suspect that all those *dm are possibly affected.