python-pynetdicom fails to build with Sphinx 4.0.2 in Fedora 35 (currently Rawhide).

+ make -C docs SPHINXBUILD=sphinx-build-3 html
make: Entering directory '/builddir/build/BUILD/pynetdicom-1.5.7/docs'
# These two lines make the build a bit more lengthy, and the
# the embedding of images more robust
rm -rf _build/html/_images
#rm -rf _build/doctrees/
sphinx-build-3 -b html -d _build/doctrees   . _build/html
Running Sphinx v4.0.2
/builddir/build/BUILD/pynetdicom-1.5.7/build_tools/sphinx
Failed to execute git to get revision
making output directory... done
Exception occurred:
  File "/builddir/build/BUILD/pynetdicom-1.5.7/docs/conf.py", line 306, in setup
    app.add_stylesheet('css/pynetdicom.css')
AttributeError: 'Sphinx' object has no attribute 'add_stylesheet'

For the logs from testing build attempts, see:
https://copr.fedorainfracloud.org/coprs/ksurma/pygments-2.9.0/package/python-pynetdicom/


Possible solution for this issue:
In some cases it may be enough to replace the call to 'add_stylesheet' with 'add_css_file' instead.

You can test you package using Koji scratch build
koji build --scratch <srpm>


For details regarding the Sphinx change, see https://fedoraproject.org/wiki/Changes/Sphinx4
Let us know here if you have any questions. Thank you!