google app engine - Up-to-date pip with AppEngine Python flex env?

Question

I want to move an app from the Python 3.7 standard environment to the Python 3.6 flex environment.

Python 3.7 comes with pip 18, Python 3.6 comes with pip 9. Pip 10 introduced a very useful feature, build dependencies. Many analytics packages need this to work, otherwise you have to install build dependencies like Cython manually in a separate step. That is obviously a non-starter in GAE.

Outside of GAE the solution is pip install --upgrade pip.

Is it possible to have the Python 3.6 environment update its pip before it runs pip install -r requirements.txt?

Adding pip to requirements.txt has no effect.

Answer 1

Waitting for answers