Shallow copy issue with rspec metadata

rspec_shallow_dup_spec.rb

describe 'outer', :one => { :two => 2 } do
  context 'inner1' do
    before do
      example.metadata[:one][:three] = 3
    end
    it 'should have 3' do
      example.metadata[:one][:three].should == 3
    end
  end
  context 'inner2' do
    it 'should not have 3' do
      example.metadata[:one][:three].should be_nil # FAIL
    end
  end
end