My first question on Ask Ubuntu: Why is firefox trying to access fstab and how can I stop it?
So I had to repave my primary workstation to fix a problem with my ZFS configuration (my ashift setting was causing problems) and things are mostly back online, but I wasn’t able to print from firefox for some reason.
I think the problem was that I had installed firefox prior to adding the printer. Anyway, long story short, this command seemed to fix the problem for me:
# snap connect firefox:cups-control
So I read this and this and solved my problem. Basically I bind /temp/download to /media/$USER/download and then I can set the download directory in Chromium and Firefox snaps to /media/$USER/download and my downloads go where I want them. This was actually harder to figure out than it should have been.