Bug#619295: Happens reliably on upgrade to 6.0.2

[John Winters]

I've had this happen on both the systems which I've tried to upgrade to 
6.0.2 using the Gnome update manager application.  Both were up to date 
with security patches and both displayed the above symptoms as soon as 
update-manager-gnome attempted to do the 6.0.2 upgrade.

Most of my systems are headless and upgraded fine with a simple "apt-get 
upgrade".  The two on which I had the problem also upgraded fine with 
this method once I'd killed the runaway process.  In case it's relevant, 
both are amd64 systems.

John