Check return result from Py_InitModule*().  This API can fail.

Probably should be backported.
diff --git a/Modules/fcntlmodule.c b/Modules/fcntlmodule.c
index 624019d..4197339 100644
--- a/Modules/fcntlmodule.c
+++ b/Modules/fcntlmodule.c
@@ -583,6 +583,8 @@
 
 	/* Create the module and add the functions and documentation */
 	m = Py_InitModule3("fcntl", fcntl_methods, module_doc);
+	if (m == NULL)
+		return;
 
 	/* Add some symbolic constants to the module */
 	d = PyModule_GetDict(m);