relax Cython req, make build work with old setuptools

vagrant · aholmberg · commit ac25d94ecd66 · 2015-09-10T15:27:17.000-05:00
see diff for explanation of old setuptools issue
PYTHON-396
diff --git a/setup.py b/setup.py
@@ -178,6 +178,25 @@ def __init__(self, ext):
 build_concurrency = int(os.environ.get('CASS_DRIVER_BUILD_CONCURRENCY', '0'))
 
 
+class NoPatchExtension(Extension):
+
+    # Older versions of setuptools.extension has a static flag which is set False before our
+    # setup_requires lands Cython. It causes our *.pyx sources to be renamed to *.c in
+    # the initializer.
+    # The other workaround would be to manually generate sources, but that bypasses a lot
+    # of the niceness cythonize embodies (setup build dir, conditional build, etc).
+    # Newer setuptools does not have this problem because it checks for cython dynamically.
+    # https://bitbucket.org/pypa/setuptools/commits/714c3144e08fd01a9f61d1c88411e76d2538b2e4
+
+    def __init__(self, *args, **kwargs):
+        # bypass the patched init if possible
+        if Extension.__bases__:
+            base, = Extension.__bases__
+            base.__init__(self, *args, **kwargs)
+        else:
+            Extension.__init__(self, *args, **kwargs)
+        
+
 class build_extensions(build_ext):
 
     error_message = """
@@ -279,7 +298,9 @@ def _setup_extensions(self):
                         for m in cython_candidates],
                     nthreads=build_concurrency,
                     exclude_failures=True))
-                self.extensions.extend(cythonize("cassandra/*.pyx", nthreads=build_concurrency))
+
+                self.extensions.extend(cythonize(NoPatchExtension("*", ["cassandra/*.pyx"], extra_compile_args=compile_args),
+                                                 nthreads=build_concurrency))
             except Exception:
                 sys.stderr.write("Failed to cythonize one or more modules. These will not be compiled as extensions (optional).\n")
 
@@ -297,7 +318,7 @@ def run_setup(extensions):
     kw['ext_modules'] = [Extension('DUMMY', [])]  # dummy extension makes sure build_ext is called for install
 
     if try_cython:
-        kw['setup_requires'] = ['Cython >=0.21']
+        kw['setup_requires'] = ['Cython>=0.20']
 
     dependencies = ['six >=1.6']
 
