blender-archive/doc/python_api/rst/info_gotcha.rst

Sphinx Warnings

Traceback (most recent call last):
  File "/var/lib/gitea/custom/sphinx/venv/bin/sphinx-build", line 5, in <module>
    from sphinx.cmd.build import main
ModuleNotFoundError: No module named 'sphinx'

Note the preview is not accurate and warnings may not indicate real issues.