I had Gramps 5.2.4 running on macOS (15.3.1) and ran brew upgrade without thinking much of it. When I came back to Gramps later it was showing an exception dialog and wasn’t responding to my attempts to quit, so I force quit it.
I reopened Gramps and no family trees were listed. At this point I realised brew had updated it to 6.0.0. I tried reinstalling the 5.2.4 .dmg but still nothing listed.
Looking in /Users/<user>/Library/Application Support/gramps it seems that there is no sqlite database at all. I will try to restore from a backup, but does anyone know what might have happened here?
Thank you Brian - I was able to track that file down at /Users/<user>/.local/share/gramps and set /Users/<user>/.local/share/gramps/grampsdb as my database path. The family trees reappeared and the upgrade seems to have gone fine.