I\'ve installed virtualenv via pip and get this error after creating a new environment:
selenium:~ auser$ virtualenv new
New pyt
I got the same problem and I found that it happens when you do not specify the python executable name properly. So for python 2x, for example:
virtualenv --system-site-packages -p python mysite
But for python 3.6 you need to specify the executable name like python3.6
virtualenv --system-site-packages -p python3.6 mysite