Created attachment 144827 [details]
Syslog with nouveau events leading to hard lock

Attached is a /var/log/syslog snip showing many events leading to the hard
lock, followed by a trimmed reboot trace showing the nouveau configuration.
Kernel is generic Linux ceo1homenx 5.2.0-8-generic #9-Ubuntu SMP Mon Jul 8
13:07:27 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Context is:  a development system left for the night, crashed after perhaps 10
hours of idleness.  System is not a server for anything, not running any vms. 
Running apps of note was an email client and web browser, otherwise just basic
KDE.  Compositor was off.