pip install git repo - installation successful but import fails

Question

I have 2 git repositories lets call them Framework and Workflows. While running the Workflows i need to install the Framework repo using pip3.

setup.py of Frameworks looks like this:

from distutils.core import setup 
setup(name='athena',
      version='0.0.1',
      py_modules=['main']
      )

I am trying to install the Framework repo using this command:

pip3 install --user -e git+https://${Personal_access_token}@github.com/athena.git@develop#egg=athena

My pip3 version is pip-22.0.4 . The installation is successful and the code of athena/framework gets downloaded .

But when i try to

import main

it fails with Module not found error.

This setup used to work until i had python 3.6 and started to appear only after i upgraded to python 3.8 .

What have i tried:

1. Tried installing it in a virtualenv - this works perfectly with the same python3.8 setup
2. Tried reverting back to python 3.6 and pip-9.0 and installing - works fine
3. Cloning the package and building the package - failed

I have no clue why it works with python3.6 and pip-9 combo but not with python3.8 and pip-22 combo . OS is ubuntu 20.04 for python3.8 and ubuntu 18.04 for python3.6

Any help will be very much appreciated.