A few questions for Russell:

>What hardware architecture are you compiling for? If it's ARM64, and you're not using a trunk version of libffi, that segfault in test_ctypes is to be expected.

Does this mean I can safely ignore the segfault?

>Are you using the libffi sources vendored into the Python source tree, or a more recent version? 

By 'vendored in' do you mean 'sources included in python source tree for building?'

>I can verify that libffi v3.2 works on ARMv7 (on iOS, anyway), and there's been plenty of changes to the ARM source tree since the Python version was vendored in.

Would your recommend downloading and building libffi from sources (on device) and then building python?

I'm asking the above questions because I've hit a fairly significant roadblock; I'm still getting the segfault when test_ctypes is run and I can't seem to get anything useful out of gdb.