memory leak object reference graph

gistfile1.rb

$ cat app/api/v2/debug.rb
module Api; module V2
  class Foobar; end
  class Debug < Api::Base
    get '/' do
      @foobar = Foobar.new
      bldr :'debug/index'
    end
  end
end; end
 
$ cat app/views/debug/index.bldr
attribute :foobar, 1
 
 
# add racksh to Gemfile :devopment and :czar
$ rbenv shell 1.9.3-p392-ref
$ bundle install
$ RACK_ENV=czar bundle exec racksh 
$rack.get '/v2/debug'
GC.start
foobar = ObjectSpace.each_object(Api::V2::Foobar).first
require 'object_graph'
ObjectGraph.new(foobar).view!