Incorrect Dependency Installation Order

[harshsingh-24]

Following the installation steps, while running pip install mmcv-full==1.2.7 leads to this error:

Collecting mmcv-full==1.2.7
  Using cached mmcv-full-1.2.7.tar.gz (231 kB)
    ERROR: Command errored out with exit status 1:
     command: 'D:\Software\Anaconda\python.exe' -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\intel\\AppData\\Local\\Temp\\pip-install-rmjilsef\\mmcv-full\\setup.py'"'"'; __file__='"'"'C:\\Users\\intel\\AppData\\Local\\Temp\\pip-install-rmjilsef\\mmcv-full\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\intel\AppData\Local\Temp\pip-install-rmjilsef\mmcv-full\pip-egg-info'
         cwd: C:\Users\intel\AppData\Local\Temp\pip-install-rmjilsef\mmcv-full\
    Complete output (5 lines):
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "C:\Users\intel\AppData\Local\Temp\pip-install-rmjilsef\mmcv-full\setup.py", line 121, in <module>
        major, minor, *rest = cv2.__version__.split('.')
    AttributeError: module 'cv2' has no attribute '__version__'
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

This seems to be avoided by running the commands in the new order:

conda create -n oln python=3.7 -y
conda activate oln
conda install pytorch=1.7.0 torchvision cudatoolkit=11.0 -c pytorch -y
pip install -r requirements.txt
pip install mmcv-full==1.2.7
pip install -v -e . 

As pip install -r requirements.txt seems to satsify the error AttributeError: module 'cv2' has no attribute '__version__' encountered in pip install mmcv-full==1.2.7