I've seen this reported many times, but never seen the issue I had, so for future reference:
Followed instructions on debugging and traced the issue down to the files in "~/.config/sublime-text-3/Packages/User/Package Control.cache" belonging to root rather than my user. Sublime is set up to share configuration via dropbox, so it's possible I opened Package Control while running Sublime as root and that's how the ownership of the cache files got set that way.
Once found, the solution was to change file ownership.
I've seen this reported many times, but never seen the issue I had, so for future reference:
Followed instructions on debugging and traced the issue down to the files in "~/.config/sublime-text-3/Packages/User/Package Control.cache" belonging to root rather than my user. Sublime is set up to share configuration via dropbox, so it's possible I opened Package Control while running Sublime as root and that's how the ownership of the cache files got set that way.
Once found, the solution was to change file ownership.