I had to revert this on my machine, as it breaks the entire rewrite installation; oddly, trying the import a second time gives a different error message:
Sorry for that. It seems my edits to config2.py were not committed (I think I committed from the pywikibot/userinterfaces directory, which doesn't show changes higher up - in svn, at least). I have now committed those, as well as the updated tests: r11648 and r11649.