I installed R4 openVINO in November 2018 and either didn't have this issue, or the R4 install instructions (pre Dec 19) didn't have me run the same demo_squeezenet_download_convert_run.sh script as the initial verification.
I installed R5 yesterday and and the verification script fails with:
from pip import main
ImportError: cannot import name 'main"
I went back to the system I'd installed R4 on to see what is going on and it failed this time. I assume its something with the virtual environment setup or some recent Ubuntu updates.
Short answer, I got the verification script to run by changing line 128 in the R4 demo_squeezenet_download_convert_run.sh
to be pip_binary=pip instead of pip_binary=pip3
I assume the same change will verify my R5 installation, I'll follow up if it does not.