I can't reproduce:

>>> from importlib import abc
>>> from . import util
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: cannot import name 'util' from '__main__' (unknown location)
>>> import importlib.util
>>>

Did you happen to do an `import *` prior to this in your REPL? If so that might explain it as you could have pulled in __package__ and such and that's used to resolve relative imports.