#2803: fix wrong invocation of heappush in seldom-reached code.

Thanks to Matt Harden.

Lib/sched.py

@@ -117,7 +117,7 @@ class scheduler:
                     action(*argument)
                     delayfunc(0)   # Let other threads run
                 else:
-                    heapq.heappush(event)
+                    heapq.heappush(q, event)
 
     @property
     def queue(self):