CI/CD error

Error: listen EADDRINUSE: address already in use :::3000

Something is already bound to the port your app/test server is trying to use on the CI runner.

Why this happens

A previous job/step on a reused runner didn't shut its server down cleanly
Two jobs on a shared runner picked the same hardcoded port

How to fix it

Kill any process left listening on the port before starting a new one, or use a fresh container per job
Prefer a dynamically assigned port (port `0`) or a per-job unique port instead of a hardcoded one on shared infrastructure