Sphinx: Read The Docs: git-lfs support. Add this piece of code at the beginning of the conf.py to support resources stored in git-lfs in readthedocs.org

conf.py

# correct the issue : pdf generation fails after a 'libpng error: Not a PNG file' 
# See https://github.com/readthedocs/readthedocs.org/issues/6770

# gist source: https://gist.github.com/Abdelkrim/c1d7005feccbcfa66b198151dc1c4abd

# -- manage git-lfs ----------------------------------------------------------
import os

if not os.path.exists('./git-lfs'):
    os.system('wget https://github.com/git-lfs/git-lfs/releases/download/v2.7.1/git-lfs-linux-amd64-v2.7.1.tar.gz')
    os.system('tar xvfz git-lfs-linux-amd64-v2.7.1.tar.gz')
    os.system('./git-lfs install')  # make lfs available in current repository
    os.system('./git-lfs fetch')  # download content from remote
    os.system('./git-lfs checkout')  # make local files to have the real content on them