python 3.9 feature not detected: argparse.BooleanOptionalAction

[ollieparanoid]

Describe the bug
argparse.BooleanOptionalAction is a Python 3.9 feature, but vermin doesn't detect it.

To Reproduce

Example code:

#!/usr/bin/env python3
ret = subparser.add_parser("qemu")
ret.add_argument("--efi", action=argparse.BooleanOptionalAction, help="...")

Running vermin -t=3.7- on it doesn't report that argparse.BooleanOptionalAction is only available in Python >=3.9.

See https://docs.python.org/3/library/argparse.html.

Expected behavior
Report that argparse.BooleanOptionalAction is only available in Python >=3.9.

Environment (please complete the following information):
vermin version: 1.5.1

[netromdk]

Thanks for reporting this.

I already have the rule in place for argparse.BooleanOptionalAction.
But I actually found an error in the visitation of the AST where keyword values wouldn't be traversed correctly!

By fixing that, it reports the following for your input file (-vvv -t=3.7-):

!2, 3.9      /tmp/test.py
  L3: 'argparse.BooleanOptionalAction' member requires !2, 3.9

Minimum required versions: 3.9
Incompatible versions:     2
Target versions not met:   3.7-