shtab tripped up by Waydroid argparse parser with subcommands.

[nt8r]

I'm using shtab 1.7.2.dev0+g61ec99d.d20241116 on Arch Linux, trying to generate tab completion for Waydroid. Waydroid installs to /usr/lib/waydroid without installing itself as a python module, so I first cd /usr/lib/waydroid. Then, running shtab tools.helpers.arguments generates a usage error from the Waydroid parser:

$ shtab tools.helpers.arguments       
usage: waydroid [-h] [-V] [-l LOG] [--details-to-stdout] [-v] [-q] [-w] {status,log,init,upgrade,session,container,app,prop,show-full-ui,first-launch,shell,logcat} ...
waydroid: error: argument action: invalid choice: 'tools.helpers.arguments' (choose from status, log, init, upgrade, session, container, app, prop, show-full-ui, first-launch, shell, logcat)

The "invalid choice" indicates that the module path is getting interpreted as a subcommand, so I figured this is what the --prog shtab option is for.

Trying shtab --prog=status tools.helpers.arguments produces the exact same output as before.

Trying shtab --prog status tools.helpers.arguments (space instead of equals) results in Waydroid's parser complaining:

waydroid: error: unrecognized arguments: --prog tools.helpers.arguments

At this point I gave up. I'm not sure what's going wrong here, but I figured it's worth reporting. For others trying to autocomplete Waydroid, it turns out that it does have argcomplete support, and that works.

[casperdcl]

It's because the function is returning args instead of parser, vis. waydroid@45ded8c:/tools/helpers/arguments.py:168.

This is probably bad practice, and worth opening an issue on Waydroid. Usually only __name__ == "__main__" guarded code should run parse_args(). Right now you can't even python -c "import tools"