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

Rails
1

$ 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:innew’
    /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:infull_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.