n, err := c.Write(b)
		if err != nil {
			return err
		}
		if n != len(b) {
			return fmt.Errorf(`Only %d chars of string "%s" sent`, n, data)
		}
		return nil
	}

	if envaddr := os.Getenv("GOTEST_DIAL_ADDR"); envaddr != "" {
		// In child process.
		c, err := Dial("tcp", envaddr)
		if err != nil {
			t.Fatal(err)
		}
		fmt.Printf("sleeping\n")
		time.Sleep(time.Minute) // process will be killed here
		c.Close()