Unable to extract symbols from cython

[chrisburr]

In numpy randint is not found (along with everything else from mtrand):

from symbol_exporter.python_so_extractor import CompiledPythonLib
lib = CompiledPythonLib("lib/python3.9/site-packages/numpy/random/mtrand.cpython")
lib.find_symbols()  # == {'methods': [], 'objects': [], 'name': 'mtrand', 'docstring': None}

Disassembling the binary in Ghidra shows that the module's PyInit function is trivial:

void PyInit_mtrand(void)
{
  PyModuleDef_Init(__pyx_moduledef);
  return;
}

though __pyx_moduledef is empty. Something must be filling it though I'm not sure what so I'll have to debug with gdb.