def fail(message, print_usage = false)
      puts "** #{message}"
      puts Usage.scan(__FILE__) if print_usage
      exit(1)
    end
def fail(message, print_usage = false)
      puts "** #{message}"
      puts Usage.scan(__FILE__) if print_usage
      exit(1)
    end
Print error on console and exit abnormally

 === Parameters
 message(String):: Error message to be displayed
 print_usage(Boolean):: Whether to display usage information

 === Return
 never