0.5.11: documentation build fails with sphinx 8.x

[kloczek]

Looks like something needs to be updated in conf.py

+ /usr/bin/sphinx-build -n -T -b man docs/source build/sphinx/man
Running Sphinx v8.0.2
WARNING: Invalid configuration value found: 'language = None'. Update your configuration to a valid language code. Falling back to 'en' (English).
loading translations [en]... done
making output directory... done
WARNING: html_static_path entry '_static' does not exist
Converting `source_suffix = '.rst'` to `source_suffix = {'.rst': 'restructuredtext'}`.
ERROR: Invalid value `None` in intersphinx_mapping['https://docs.python.org/']. Expected a two-element tuple or list.

Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/sphinx/cmd/build.py", line 332, in build_main
    app = Sphinx(args.sourcedir, args.confdir, args.outputdir,
  File "/usr/lib/python3.10/site-packages/sphinx/application.py", line 277, in __init__
    self.events.emit('config-inited', self.config)
  File "/usr/lib/python3.10/site-packages/sphinx/events.py", line 100, in emit
    results.append(listener.handler(self.app, *args))
  File "/usr/lib/python3.10/site-packages/sphinx/ext/intersphinx/_load.py", line 127, in validate_intersphinx_mapping
    raise ConfigError(msg)
sphinx.errors.ConfigError: Invalid `intersphinx_mapping` configuration (1 error).

Configuration error:
Invalid `intersphinx_mapping` configuration (1 error).

[efiring]

The last line in your conf.py needs to be modified to match
https://www.sphinx-doc.org/en/master/usage/extensions/intersphinx.html.
That will at least allow the build to proceed with Sphinx 8.x. I don't
know whether it will still work with earlier versions.