python 3.7 venv broken after upgrade to Ubuntu 20.04

Question

I've just upgraded to Ubuntu 20.04. I was working with a python 3.7 project using Django inside a virtual environment, so I was confident even with the upgraded distro (which involved the installation of python 3.8) my venv would still worked. Unfortunately, that's not the case: when I activate my venv, the interpreter of python is still the 3.8 version, and nothing works. python 3.7 is completely missing. What can I do to restore my project?

Answer 1

Same problem for me. This is my solution if you do not want to upgrade everything (perhaps not all package are upgradable).

1. Install python 3.7 which is gone with upgrade to ubuntu 20

   sudo add-apt-repository ppa:deadsnakes/ppa
   sudo apt-get update
   sudo apt-get install python3.7
   

2. in your virtualenv dir (e.g env/) edit last line in pyenv.cfg

   version = 3.7
   

3. set back soft link of python3 in env/bin linking back to 3.7

   ln -s  /usr/bin/python3.7 python3
   

You may need to delete old symlik before creating new one

Now, should work: it does for me!