Can't figure out `Help()` for arg

[ybizeul]

I'm basically trying to document a complex arg with Help() to no avail.

package main

import "github.com/alecthomas/kong"

var CLI struct {
	CmdTest commandWithHelp `cmd:""`
}

type commandWithHelp struct {
	Test argumentWithHelp `arg:"" help:"Test"`
}

type argumentWithHelp struct {
	Test string `arg:""`
}

func (u *argumentWithHelp) Help() string {
	return `Some longer text`
}

func (u *commandWithHelp) Run(ctx *kong.Context) error {
	return nil
}

func main() {

	ctx := kong.Parse(&CLI, kong.ConfigureHelp(kong.HelpOptions{
		Compact: true,
		Summary: false,
	}))
	_ = ctx.Run()
}

❯ go run . cmd-test -h
Usage: kongtest cmd-test <command>

Flags:
  -h, --help    Show context-sensitive help.

Commands:
  cmd-test <test>    Test

1. For some reason, kong thinks that cmd-test has a cmd-test subcommand
2. Long description for test isn't called or displayed