target_cfg fails in OS X

[Downchuck]

From a fresh clone of noVNC calling a fresh websockify:

$ ./utils/launch.sh 
readlink: illegal option -- f
usage: readlink [-n] [file ...]
Warning: could not find self.pem
Using local websockify at /Users/..../Desktop/noVNC/websockify/run
Starting webserver and WebSockets proxy on port 6080
Traceback (most recent call last):
  File "/Users/.../Desktop/noVNC/websockify/run", line 5, in <module>
    websockify.websocketproxy.websockify_init()
  File "/Users/..../Desktop/noVNC/websockify/websockify/websocketproxy.py", line 436, in websockify_init
    server = WebSocketProxy(**opts.__dict__)
  File "/Users/..../Desktop/noVNC/websockify/websockify/websocketproxy.py", line 232, in __init__
    websocket.WebSocketServer.__init__(self, RequestHandlerClass, *args, **kwargs)
TypeError: __init__() got an unexpected keyword argument 'target_cfg'
Failed to start WebSockets proxy

WebSocketServer does not have any references to target_cfg.