exp: tentative fixup

Author: neutrinoceros

setup.py

@@ -5,6 +5,7 @@
 
 from Cython.Build import cythonize
 from setuptools import Command, Extension, setup
+from setuptools.command import build_ext
 
 
 BASEDIR = os.path.abspath(os.path.dirname(__file__))
@@ -68,6 +69,12 @@ def run(self):
                     else:
                         print('clean: skipping file {!r}'.format(artifact))
 
+class BuildExt(build_ext):
+    def finalize_options(self) -> None:
+        super().finalize_options()
+        for ext in self.extensions:
+            ext.py_limited_api = USE_PY_LIMITED_API
+
 
 if ((FLAG_COVERAGE in sys.argv or os.environ.get('CYTHON_COVERAGE', None))
     and cythonize):
@@ -99,7 +106,7 @@ def run(self):
     )
 
 setup(
-    cmdclass={'clean_cython': CleanCython},
+    cmdclass={'clean_cython': CleanCython, 'build_ext': BuildExt},
     ext_modules=ext_modules,
     options=SETUP_OPTIONS,
 )