"--group-filter -backend" doesn't work

[icy]

I want to exclude some group when run west update, and it seems the exclusion option doesn't work as the minus was considered as another (unknown?) option:

$ west update --group-filter -backend
usage: west update [-h] [--stats] [--name-cache NAME_CACHE] [--path-cache PATH_CACHE] [-f {always,smart}] [-o FETCH_OPT] [-n] [-k] [-r] [--group-filter FILTER] [-x] [PROJECT ...]
west update: error: argument --group-filter/--gf: expected one argument

[icy]

The work-around is to use non-space version in arguments, i.e, --gf=-backend or --group-filter=-backend, but that is still a problem with our argument parsing. What is our expected behavior here? I can help to submit a patch once it's clear.

btw, I'm using west for my own projects. I hope west is my last tool after many tries [1] ;)

[1] https://github.com/icy/git_xy#meta-repository

[marc-hb]

This is not caused by west but by Python's standard argparse library. This is the way argparse chooses to resolve the ambiguity and will behave the same with all Python programs using argparse (= most Python programs?)

Try running this:

#!/usr/bin/python3

import argparse

parser = argparse.ArgumentParser(prog='PROG')
parser.add_argument('--group-filter')

# parser.parse_args(['--group-filter', 'groupA'])  # OK
# parser.parse_args(['--group-filter=-groupB']) # OK
parser.parse_args(['--group-filter', '-groupC'])  # fails "expected one argument"

btw, I'm using west for my own projects. I hope west is my last tool after many tries [1] ;)

:-)

[mbolivar-nordic]

Right. This is an argparse thing, not a west issue. The right way to pass option values which begin with - is to use = as a separator instead of whitespace. There's nothing for west to do here. We can't rewrite the argument parsing to use something other than the standard argparse library because that's the interface that extensions use to register their arguments.

I don't see it as a problem but just a fact of life when using argparse, so I'm going to close this issue. Thanks for taking the time to file it and I hope the discussion is helpful to future readers.