Ruby 1.9 slow require WTF

slow_require.log

> cat 1.rb 
gem 'facets', '2.8.4'
require 'facets'

 > /usr/bin/time -p ruby -v 1.rb     
ruby 1.8.7 (2010-01-10 patchlevel 249) [i686-linux]

real 0.39
user 0.03
sys 0.16

> /usr/bin/time -p ruby -v 1.rb
ruby 1.9.2dev (2010-04-02 trunk 27162) [i686-linux]

real 6.42
user 2.12
sys 0.92

> ruby-prof 1.rb # with ruby 1.9.2dev (2010-04-02 trunk 27162) [i686-linux]
Thread ID: 76994260
Total: 2.310000

 %self     total     self     wait    child    calls  name
 71.43      2.12     1.65     0.00     0.47      377  Kernel#require(d2)
 16.02      0.44     0.37     0.00     0.07      101  Kernel#require(d3)
  7.79      2.30     0.18     0.00     2.12       39  Kernel#require(d1)
  1.73      0.04     0.04     0.00     0.00    20979  Hash#default
  0.87      0.03     0.02     0.00     0.01        9  Kernel#require(d4)
  0.43      0.01     0.01     0.00     0.00       27  <Class::Dir>#[]
  0.43      0.01     0.01     0.00     0.00        5  Array#select
  0.43      0.01     0.01     0.00     0.00      847  Module#method_added
  0.43      2.31     0.01     0.00     2.30        1  Kernel#load
  0.43      0.01     0.01     0.00     0.00        3  Kernel#require(d5)