Exactly what command did you run? I can't reproduce this:
% pip install world Collecting world Using cached world-3.1.1-py2.py3-none-any.whl Collecting setuptools (from world) Using cached setuptools-20.10.1-py2.py3-none-any.whl Installing collected packages: setuptools, world Successfully installed setuptools-20.10.1 world-3.1.1 % pip --version pip 8.1.1 from /usr/lib/python2.7/dist-packages (python 2.7) % dpkg-query -W python-pip python-pip 8.1.1-2