Error running pip install command

[nimitbhargava]

I ran the command pip install git+git://github.com/reillysiemens/wb2k.git and facing this issue.

➜  Experiments sudo pip install git+git://github.com/reillysiemens/wb2k.git

Password:
The directory '/Users/nimit/Library/Caches/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/Users/nimit/Library/Caches/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting git+git://github.com/reillysiemens/wb2k.git
  Cloning git://github.com/reillysiemens/wb2k.git to /private/tmp/pip-req-build-rm17ZN
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/tmp/pip-req-build-rm17ZN/setup.py", line 6, in <module>
        from pip.req import parse_requirements
    ImportError: No module named req

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/tmp/pip-req-build-rm17ZN/