Any one going through similar issue, when upgrade failing at db migrate
Did below, upgrade was success!
Start the container, since it’s stopped during upgrade
./launcher start app
./launcher enter app
Enter into psql command prompt
sudo -u postgres psql discourse
see the triggers
SELECT tgname FROM pg_trigger;
Drop the trigger
DROP TRIGGER IF EXISTS bookmarks_polymorphic_data_sync ON bookmarks CASCADE;
Rebuild now
./launcher rebuild app