json2msgpack utility doesn't work

[rgrinberg]

After installing on OSX and running echo '[1, 2, 3]' | json2msgpack I get:

net.js:51
  throw new TypeError('Unsupported fd type: ' + type);
        ^
TypeError: Unsupported fd type: TTY
    at createHandle (net.js:51:9)
    at new Socket (net.js:156:20)
    at Socket.<anonymous> (/usr/local/lib/node_modules/msgpack/bin/json2msgpack:14:9)
    at Socket.emit (events.js:117:20)
    at _stream_readable.js:944:16
    at process._tickCallback (node.js:442:13)