I am running the test suite now using the "secret" attribute on ImportError. I tried to pass a flag, but locking became a bit messy/complicated. And I also realized that if I didn't do this then using different implementation of import_ in importlib wouldn't work because I would be hard-coding in what import implementation was used which would bypass the accelerated code in import.c. Plus with the compatibility issues I have had in the passed, I didn't want to skip a step of import that someone was probably relying on.

Once Python 3.4 comes out I will create a new exception that is raised when no module is found and catch that class specifically to avoid this hack.