We are using some compiled cython modules with c++ 11 features.
This prohibits us from instructing users to install python from the python.org download.

Please consider using clang with support for C++ 11 and higher.
This would move the minimum OS X version away from 10.6 but as 10.6 is 8 years old and phased out 6 years ago it should be rare that non technical users would be using this OS version.