> All it means is that you can't make an assertion in the spec that
> conflicts with how the language is engineered, and that's always true
> :-)

I guess there's something to that.  Here's a good workaround that
doesn't pollute and works on 1.8 and 1.9... evade the block by
foregoing describe.

  module A
    module B
    end
  end

  # This passes on both ruby 1.8 and 1.9 and doesn't pollute.
  class MiniTestIncludes < MiniTest::Spec
    include A

    it "should show inclusion works" do
      B.must_equal A::B
    end
  end