PYTHON setup.py build_ext --inplace
PYTHON -c "import a; import sys; sys.exit(a.compile_env_test())"

######## setup.py ########

from distutils.core import setup
from Cython.Distutils.extension import Extension
from Cython.Distutils.old_build_ext import old_build_ext

setup(
  cmdclass = {'build_ext': old_build_ext},
  ext_modules = [Extension(
    "a", ["a.pyx"],
    pyrex_compile_time_env = {'TEST': True},
  )],
)

######## a.pyx ########
def compile_env_test():
    IF TEST:
        return 0
    ELSE:
        return 1