//
// This function re-executes the same executable as a child process,
// in a special mode. In that mode, the call to monitor will never
// return.
func monitor() {
	const monitorVar = "RUNTIME_DEBUG_MONITOR"
	if os.Getenv(monitorVar) != "" {
		// This is the monitor (child) process.
		log.SetFlags(0)
		log.SetPrefix("monitor: ")

		crash, err := io.ReadAll(os.Stdin)
		if err != nil {