log.SetFlags(0)
	log.SetPrefix("bisect: ")

	var b Bisect
	b.Stdout = os.Stdout
	b.Stderr = os.Stderr
	flag.IntVar(&b.Max, "max", 0, "stop after finding `m` failing change sets")
	flag.IntVar(&b.MaxSet, "maxset", 0, "do not search for change sets larger than `s` elements")
	flag.DurationVar(&b.Timeout, "timeout", 0, "stop target and consider failed after duration `d`")