lsof -c octopi, forced another quit, removed two temporary files (the first of which was explicitly a
lockfile, the second was a stream), reopened Octopi, no better.
lsof -c octopi, forced another quit, removed two more recent temporary files from the same path:
[momh167-gjp4-virtualbox-manjaro ~]# rm /tmp/qtsingleapp-Octopi-1d88-3e8-lockfile
[momh167-gjp4-virtualbox-manjaro ~]# rm /tmp/qtsingleapp-Octopi-1d88-3e8
– then restarted the OS.
Thinking back to the original symptoms … the VirtualBox guest in which I run Manjaro was unused for maybe a few weeks. Expecting updates to be applicable, I vaguely recall being surprised by the absence of the icon for
octopi-notifier … then manually starting Octopi and running a check for updates. It responded but gave an unexpected response (I can’t recall what, exactly) … that’s probably when I first forced a quit. I was warned against doing so but I proceeded, thinking that no harm would come.
In retrospect, I should have thought of lock files before anything else.