Failed to start devlopment server — BindError: Unable to find a consistent port localhost

Question

Google-app-engine development server runs great yesterday, but when I try to start it today. It only shout out this Error.

I tried use lsof -i:8080 / <

Answer 1

I solved this issue by passing an explicit api port to dev_appserver.py:

dev_appserver.py path/to/project --api_port 3000

I was unable to solve the issue by editing the hosts file or passing --port / --host to dev_appserver.py.

I didn't identify the root cause.