ooni instructions say to use mkvirtualenv; wheezy doesn't easily have it
https://github.com/hellais/ooni-probe#getting-started says to apt-get install python-virtualenv virtualenvwrapper, and then has you run mkvirtualenv.
Apparently there is some extra implicit step I'm supposed to do.
At the least, your instructions should acknowledge that they won't work for wheezy users. Better is to make them work. :)