foobar.c

#include <greenlet/greenlet.h>

setup.py

from distutils.core import setup
from distutils.extension import Extension

setup(
    name='foobar',
    ext_modules=[Extension('foobar', sources=['foobar.c'])],
)

testme.sh

#!/bin/bash
set -e
(cd $HOME/src/Python-3.5.0 && ./configure --prefix=/tmp/python-3.5.0 && make && make install)
/tmp/python-3.5.0/bin/pyvenv /tmp/myenv
/tmp/myenv/bin/pip install greenlet
/tmp/myenv/bin/python3 setup.py build_ext -i