James MacAulay Has An Internet!

If you get this:

Address already in use - bind(2) (Errno::EADDRINUSE)

…do this:

$ lsof -i :3000
COMMAND  PID  USER   FD   TYPE     DEVICE SIZE/OFF NODE NAME
ruby    9736 james    7u  IPv4 0x084b4a8c      0t0  TCP *:hbci (LISTEN)
$ kill 9736

(or, with your actual port number instead of 3000)