0.1.7: sphinx warnings

+ /usr/bin/python3 setup.py build_sphinx -b man --build-dir build/sphinx
running build_sphinx
Running Sphinx v4.0.2
making output directory... done
WARNING: html_static_path entry '_static' does not exist
loading intersphinx inventory from http://docs.python.org/objects.inv...
loading intersphinx inventory from http://sphinx-doc.org/objects.inv...
intersphinx inventory has moved: http://docs.python.org/objects.inv -> https://docs.python.org/3/objects.inv
intersphinx inventory has moved: http://sphinx-doc.org/objects.inv -> https://www.sphinx-doc.org/en/master/
WARNING: failed to reach any of the inventories with the following issues:
intersphinx inventory 'http://sphinx-doc.org/objects.inv' not readable due to ValueError: unknown or unsupported inventory version: ValueError('invalid inventory header: ')
building [mo]: targets for 0 po files that are out of date
building [man]: all manpages
updating environment: [new config] 2 added, 0 changed, 0 removed
reading sources... [100%] index
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
writing... python-sphinxcontrib-autoprogram.3 { } done
build succeeded, 2 warnings.

Start by running /usr/bin/python3 setup.py build_sphinx -b man --build-dir build/sphinx and inspect the Sphinx configuration and documentation sources involved in the build. Determine the cause of the _static and intersphinx warnings; done means the man-page build completes without these warnings.