class DEBUGGER__::Session

def postmortem=(is_enable)
  if is_enable
    unless @postmortem_hook
      @postmortem_hook = TracePoint.new(:raise){|tp|
        exc = tp.raised_exception
        frames = DEBUGGER__.capture_frames(__dir__)
        exc.instance_variable_set(:@__debugger_postmortem_frames, frames)
      }
      at_exit{
        @postmortem_hook.disable
        if CONFIG[:postmortem] && (exc = $!) != nil
          exc = exc.cause while exc.cause
          begin
            @ui.puts "Enter postmortem mode with #{exc.inspect}"
            @ui.puts exc.backtrace.map{|e| '  ' + e}
            @ui.puts "\n"
            enter_postmortem_session exc
          rescue SystemExit
            exit!
          rescue Exception => e
            @ui = STDERR unless @ui
            @ui.puts "Error while postmortem console: #{e.inspect}"
          end
        end
      }
    end
    if !@postmortem_hook.enabled?
      @postmortem_hook.enable
    end
  else
    if @postmortem_hook && @postmortem_hook.enabled?
      @postmortem_hook.disable
    end
  end
end