This was broken in commit 20f672c4e6,
which reorganized the conf.py file into the html subdirectory. See:
https://github.com/pypa/pip/pull/5724https://github.com/readthedocs/readthedocs.org/issues/1543
This broke the relative manpage globbing because Sphinx will os.chdir()
into the directory location of conf.py before evaluating it, so the
globbing returned nothing at all. As a result, while the main pip(1)
manpage continued to be built, no pip-*(1) subcommand manpages were
built.
In commit d2e7377c0f, the documentation
directories were reorganized, resulting in `fname_base` (the path that
Sphinx looked for source files) to no longer expect the leading 'man/'.
This was always also stripped from the `outname`, which now strips four
characters twice over.
Fix by reducing the stripped length to only the length of the prefix in
fname_base itself.