xCode4 hangs cloning Github

I'm upgrading to xCode4 and trying to use the new clone feature to clone the route-me lib开发者_C百科rary from github. But each time, it just hangs, saying "Cloning 'route-me'" with the activity indicator swirling.

I've tried using the git:// and https:// urls suggested by githib and also http, but to no avail.

Is this a bug or am I doing something daft?

Thanks,

Chris.