As part of the PEP 451 changes, frozen imports were updated to avoid setting the __file__ attribute, as that attribute makes no sense for frozen modules.

However, _frozen_importlib isn't loaded through the normal mechanisms (they don't exist yet!), so it is still getting a __file__ attribute set. (This was discovered while investigating issue 20884)

This is a fairly harmless state of affairs, so I suggest we leave it alone in the 3.4 maintenance releases, and just tidy it up in 3.5. However, I'm also open to fixing it in 3.4.1.