Comment 14 for bug 882817

Using poweroff --force does shutdown my laptop, but I worry that might not be a graceful or safe way of doing so...

It is clearly an issue with some process not responding correctly to the request for it to quit.

If it is of relevance, I also experienced the Xauthority issue as part of the upgrade (inability to log in to account due to LightDM borking some permissions somewhere during the upgrade), so I wonder if what caused that also caused this issue...