How to fix Rails ActiveRecord::ConcurrentMigrationError

To correct an ActiveRecord::ConcurrentMigrationError when trying to run Rails databases migrations, you need to:

1. open psql
2. Select advisory locks SELECT pid, locktype, mode FROM pg_locks WHERE locktype = 'advisory';
3. Kill this scoundrels! SELECT pg_terminate_backend(<PID>);

Comments

[Marc Köhlbrugge]

Thanks for sharing! That just saved me a couple of hours figuring out what the hell was happening.

[ZeroCool]

Thank you very much!!