Sphinx Completion Bug

[psacawa]

Thanks for making this. It should be built right into argparse, but people were apprehensive. I will try to send PRs to other projects to refactor so external shtab invocation is possible.

I got an exception while doing external completion generation on sphinx:

shtab -s zsh -u sphinx.cmd.build.get_parser

  File "/home/psacawa/.pyenv/versions/3.9.0/bin/shtab", line 8, in <module>
    sys.exit(main())
  File "/home/psacawa/.pyenv/versions/3.9.0/lib/python3.9/site-packages/shtab/main.py", line 61, in main
    complete(
  File "/home/psacawa/.pyenv/versions/3.9.0/lib/python3.9/site-packages/shtab/__init__.py", line 570, in complete
    return completer(
  File "/home/psacawa/.pyenv/versions/3.9.0/lib/python3.9/site-packages/shtab/__init__.py", line 522, in complete_zsh
    root_options="\n  ".join(
  File "/home/psacawa/.pyenv/versions/3.9.0/lib/python3.9/site-packages/shtab/__init__.py", line 523, in <genexpr>
    format_optional(opt)
  File "/home/psacawa/.pyenv/versions/3.9.0/lib/python3.9/site-packages/shtab/__init__.py", line 399, in format_optional
    help=escape_zsh(opt.help or ""),
  File "/home/psacawa/.pyenv/versions/3.9.0/lib/python3.9/site-packages/shtab/__init__.py", line 361, in escape_zsh
    return RE_ZSH_SPECIAL_CHARS.sub(r"\\\1", string)
TypeError: expected string or bytes-like object

It doesn't occur for bash:

shtab -u sphinx.cmd.build.get_parser

[casperdcl]

Hmmm... due to use of sphinx.locale._TranslationProxy instead of str.

This bizarre stuff: https://github.com/sphinx-doc/sphinx/blob/f9941b9402821de2d60c1e94f9ac5cf0379640d0/sphinx/cmd/build.py#L27