当我使用requirements.txt时，请不要从virtualenv中安装到site-packages目录

I'm relatively new to running Python with virtualenv so this might be an easy fix, but I can't for the life of me figure out what's going on. I'm running Windows 7 professional x64 with Python 2.7.5 installed I have installed pip and virtualenv. I have a django project that I'm attempting to work on which I have cloned from a Heroku repository. When I attempt to set up a virtualenv and install the requirements of my project I'm running into a strange error that I can't figure out. I have everything setup as follows:I'm relatively new to running Python with virtu