Minimal reproducible example

package main

import "github.com/alecthomas/kong"

var Cli struct {
	ArgA float64 `short:"a" description:"Argument A"`
}

func main() {
	kong.Parse(&Cli)
}

The long version works as expected:

go run . --arg-a=-10

The short version:

go run . -a=-10

Errors out:

kong-issue-repro: error: --arg-a: expected a float but got "=-10" (string)
exit status 1

Context

I did look at #166 (comment), but there was no info on whether it is expected that the short and long versions behave differently.

I would be willing to contribute a fix if this is an actual bug.