puma Address already in use - bind(2) for "127.0.0.1" port 8080 code example
Example: Address already in use - bind(2) for "127.0.0.1" port 3000 (Errno::EADDRINUSE)
lsof -wni tcp:3000
kill -9 PID_number
lsof -wni tcp:3000
kill -9 PID_number