uwsgi + Flask + virtualenv ImportError: no module named site

Question

(Other posts on SO are similar, but none have the specific combination of uwsgi + Flask + virtualenv) (This one is closest)

I installed uwsgi via apt-get. I also tried

Answer 1

If your virtual environment is running on Python3 then you must install uwsgi using pip3, not pip otherwise, version mismatch will create this import problem

pip uninstall uwsgi    
pip3 install uwsgi