Got different results from D&D Agile book on test of unit test

$ ruby test/unit/pagespec_test.rb
Loaded suite test/unit/pagespec_test
Started
.E....
Finished in 0.502818 seconds.

  1) Error:
testservers(ActionController::TestCase):
ArgumentError: wrong number of arguments (0 for 1)
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
test_case
.rb:48:in `initialize'
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
test_case
.rb:48:in `new'
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/
test_case
.rb:48:in `setup_without_fixtures'
    /usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/
fixtures.rb
:979:in `full_setup'
    /usr/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/
testing/d
efault.rb:7:in `run'

6 tests, 1 assertions, 0 failures, 1 errors
---snip----
This doesn't appear to be pointing to any of my code, but rather to
rails itself. Line 48 starts as follows near the end of test_case.rb:

      @controller = self.class.controller_class.new
      @request = TestRequest.new
      @response = TestResponse.new
    end
  end
end
---snip---
Even if it's me, it would be nice if the diagnostic message were more
helpful.