I think this is the script needing updates for vivid. Just before the error we see:
> I: stopping unity8 > initctl: unable to determine sessions > initctl: unable to determine sessions > initctl: Unknown job: unity8 > I: stopping lightdm > initctl: unable to determine sessions > initctl: unable to determine sessions > initctl: Unknown instance:
Empirically, running without stopping lightdm gives a similar failure locally, while stopping it before the test gives a pass.
I think this is the script needing updates for vivid. Just before the error we see:
> I: stopping unity8
> initctl: unable to determine sessions
> initctl: unable to determine sessions
> initctl: Unknown job: unity8
> I: stopping lightdm
> initctl: unable to determine sessions
> initctl: unable to determine sessions
> initctl: Unknown instance:
Empirically, running without stopping lightdm gives a similar failure locally, while stopping it before the test gives a pass.