manuel doctests don't use the globals dictionary passed to setUp and tearDown.
This has at least 2 negative consequences:
- tearDown can't clean up things created in the tests (e.g. close databases opened in the tests).
- zope.testing.module doesn't work properly because global changes made in the tests aren't reflected in the test module.
I haven't looked at the code, but probably where manuel is now copying the dictionary, it should be copying the contents.