Describe the bug
The ensure_span_tbox_type function, exposed by the MEOS api, is undefined, making the shared library built for pymeos crash when imported.

This is most probably caused by the functions being wrapped by an #ifndef NDEBUG. Removing it solves the issue.

To Reproduce
I haven't tried to reproduce the issue with a sample C program, but following the pymeos_cffi building instructions generates the issue.

Screenshots