For a reason that I don't understand, this patch to asyncio fixes the problem:


--- a/asyncio/tasks.py	Mon Mar 31 11:31:16 2014 -0700
+++ b/asyncio/tasks.py	Sat Apr 12 20:37:02 2014 -0700
@@ -49,7 +49,8 @@
     def __next__(self):
         return next(self.gen)
 
-    def send(self, value):
+    def send(self, value, *args):
         return self.gen.send(value)
 
     def throw(self, exc):


Maybe the problem really is somewhere else, but this works.