There may be a bug in how tkinter frames are handled when called in multiple processes in OS X.

I am trying to run a simple script that defines a new Frame subclass and then attempts to call it multiple times in separate processes using the multiprocessing module. When the frame's mainloops are called the process crashes. I've included the script where this problem is occurring.

The crash report specifies python, and among a bunch of boilerplate information includes the following lines:

Application Specific Information:
*** multi-threaded process forked ***
crashed on child side of fork pre-exec

This is happening in Python 3.4.3, running in OS X 10.10.4. In testing this on alternative platforms (Windows and Linux) it appears to work, suggesting it may be a bug in OS X's implementation.