gistfile1.txt

ejucovy@hotdog:/tmp$ curl -O https://github.com/pypa/virtualenv/raw/master/virtualenv.py 
ejucovy@hotdog:/tmp$ python virtualenv.py foo
New python executable in foo/bin/python
Installing setuptools............done.
ejucovy@hotdog:/tmp$ cd foo
ejucovy@hotdog:/tmp/foo$ ./bin/pip -E /tmp/bar install Tempita
The virtual environment does not exist: /tmp/bar
and virtualenv is not installed, so a new environment cannot be created