Pip Index Page 2
OSX: Python anaconda error when installing pip
When you install pip with "conda install pip" and you got the error "CondaOSError: OS error: failed to link", try to delete the pip package from your anaconda. See here for full details on how to solve this issue.
Pip Index Page 2
Six issue when installing package on OS X 10.11 El Capitan
There is a known issue with OSX. You need to pass additional arguments to pip command in order to fix the issue.