I think the issue is that even though libcloud isn't forking anywhere, if someone else is using pycrypto and then forks to call libcloud, it can cause an error.  This is basically a safety call that just makes sure that libcloud is working from a fresh state.  (There may be a better way to do it, but this seemed to be the general suggestion when I was searching for the particular error seen by a coworker working on some different third-party code.)