log_1.6_error.rb

  # original log_error method
  def self.log_single_error(exception)
    message = "\n#{exception.class} (#{exception.message}):\n"
    message << exception.annoted_source_code.to_s if exception.respond_to?(:annoted_source_code)
    message << "  " << exception.backtrace.join("\n  ")
    $stderr.puts("#{message}\n\n")
  end


  def self.log_and_exit_if_error
    begin
      yield
    rescue => e
      print_error(e)
      exit 1
    end
  end


  def self.print_error(exception)
    steps = 30

    while true
      log_single_error(exception)
      # use begin/rescue block as respond_to is not relaible
      begin
        break if exception == exception.cause
        exception = exception.cause
      rescue
        # no cause field
        break
      end
      break unless exception
      break if steps < 0
      steps -= 1
    end
  end