I run sudo pip install git-review, and get the following messages:
Downloading/unpacking git-review
C
I used to use the easy_install pip==1.2.1 workaround but I randomly found that if you're having this bug, you probably installed a 32bit version of python.
If you install a 64bit version of it by installing it from the source and then build you virtualenv upon it, you wont have that pip bug anymore.