func (p *Parser) Fail(msg string) {
	p.WriteUsage(os.Stderr)
	fmt.Fprintln(os.Stderr, "error:", msg)
	os.Exit(-1)
}
func (p *Parser) Fail(msg string) {
	p.WriteUsage(os.Stderr)
	fmt.Fprintln(os.Stderr, "error:", msg)
	os.Exit(-1)
}
func ( p * Parser ) Fail ( msg string ) { p . WriteUsage ( os . Stderr ) fmt . Fprintln ( os . Stderr , " " , msg ) os . Exit ( - 1 ) }
// Fail prints usage information to stderr and exits with non-zero status
Fail prints usage information to stderr and exits with non - zero status