# File cli/ruby-debug/processor.rb, line 179
    def at_tracing(context, file, line)
      return if defined?(Debugger::RDEBUG_FILE) && 
        Debugger::RDEBUG_FILE == file # Don't trace ourself
      @last_file = CommandProcessor.canonic_file(file)
      canonic_file = CommandProcessor.canonic_file(file)
      unless canonic_file == @last_file and @last_line == line and 
          Command.settings[:tracing_plus]
        print "Tracing(%d):%s:%s %s",
        context.thnum, canonic_file, line, Debugger.line_at(file, line)
        @last_file = canonic_file
        @last_line = line
      end
      always_run(context, file, line, 2)
    end