# File lib/systemu.rb, line 221
  def tmpdir d = Dir.tmpdir, max = 42, &b
    i = -1 and loop{
      i += 1

      tmp = File.join d, "systemu_#{ @host }_#{ @ppid }_#{ @pid }_#{ rand }_#{ i += 1 }"

      begin
        Dir.mkdir tmp 
      rescue Errno::EEXIST
        raise if i >= max 
        next
      end

      break(
        if b
          begin
            b.call tmp
          ensure
            FileUtils.rm_rf tmp unless SystemU.turd 
          end
        else
          tmp
        end
      )
    }
  end