Detect Cython later in the build process, allowing the library to be specified in setup_requires. Fixes #288.

1 files changed, 10 insertions, 11 deletions

diff --git a/setuptools/extension.py b/setuptools/extension.py
index 8178ed33..a7c40f86 100644
--- a/setuptools/extension.py
+++ b/setuptools/extension.py
@@ -12,35 +12,34 @@ _Extension = _get_unpatched(distutils.core.Extension)
 
 msvc9_support.patch_for_specialized_compiler()
 
-def have_pyrex():
+def _have_cython():
     """
-    Return True if Cython or Pyrex can be imported.
+    Return True if Cython can be imported.
     """
-    pyrex_impls = 'Cython.Distutils.build_ext', 'Pyrex.Distutils.build_ext'
-    for pyrex_impl in pyrex_impls:
+    cython_impls = 'Cython.Distutils.build_ext',
+    for cython_impl in cython_impls:
         try:
-            # from (pyrex_impl) import build_ext
-            __import__(pyrex_impl, fromlist=['build_ext']).build_ext
+            # from (cython_impl) import build_ext
+            __import__(cython_impl, fromlist=['build_ext']).build_ext
             return True
         except Exception:
             pass
     return False
 
+# for compatibility
+have_pyrex = _have_cython
+
 
 class Extension(_Extension):
     """Extension that uses '.c' files in place of '.pyx' files"""
 
-    def __init__(self, *args, **kw):
-        _Extension.__init__(self, *args, **kw)
-        self._convert_pyx_sources_to_lang()
-
     def _convert_pyx_sources_to_lang(self):
         """
         Replace sources with .pyx extensions to sources with the target
         language extension. This mechanism allows language authors to supply
         pre-converted sources but to prefer the .pyx sources.
         """
-        if have_pyrex():
+        if _have_cython():
             # the build has Cython, so allow it to compile the .pyx files
             return
         lang = self.language or ''