# File lib/gauntlet_parsetree.rb, line 35
  def diff_pp o1, o2
    require 'pp'

    File.open("/tmp/a.#{$$}", "w") do |f|
      PP.pp o1, f
    end

    File.open("/tmp/b.#{$$}", "w") do |f|
      PP.pp o2, f
    end

    `diff -u /tmp/a.#{$$} /tmp/b.#{$$}`
  ensure
    File.unlink "/tmp/a.#{$$}" rescue nil
    File.unlink "/tmp/b.#{$$}" rescue nil
  end