Yep, I had that change too.  I think I see what's going on: the `importer_spec.rb` test calls ASpaceImport::Importer.destroy_importers before each test, and if you get unlucky with the ordering of the test suite it wipes out the existing definitions for the other importers.  I tried commenting out all of `importer_spec.rb` and then the tests run with no problem.