If you have a local folder (without an __init__.py, hence just a normal folder) with the same name as a non local module, the import statements of that module will assumed to be local and transformed from for example ``import datetime`` to ``from . import datetime``.
Not really, but they are related. The fixer looks for a local module, and if it finds it it will assume the import is local. #13317 is caused by it not finding the module, since it's not built and hence assuming it's a global import. This bug, contrariwise, is cause by the fixer finding a folder, and therefore assuming it is a local import when it's not. The fix for this is to check that the folder has an __init__.py. The fix for #13317 is to build extensions before running 2to3. Neither of them are huge problems since you can avoid both bugs but not using relative imports. :-)