diff -r ccde4da4d0de Lib/multiprocessing/pool.py
--- a/Lib/multiprocessing/pool.py	Mon Aug 24 12:56:24 2015 -0400
+++ b/Lib/multiprocessing/pool.py	Tue Aug 25 20:21:31 2015 +0200
@@ -20,6 +20,7 @@
 import os
 import time
 import traceback
+import warnings
 
 # If threading is available then ThreadPool should be provided.  Therefore
 # we avoid top-level imports which are liable to fail on some systems.
@@ -46,6 +47,10 @@
 def starmapstar(args):
     return list(itertools.starmap(args[0], args[1]))
 
+
+class WorkerTerminatedPrematurely(Warning):
+    pass
+
 #
 # Hack to embed stringification of remote traceback in local traceback
 #
@@ -209,6 +214,14 @@
         for i in reversed(range(len(self._pool))):
             worker = self._pool[i]
             if worker.exitcode is not None:
+                if worker.exitcode != 0:
+                    # worker terminated prematurely
+                    warnings.warn(
+                        "Worker %d ended prematurely with exit code %d" % (
+                            i, worker.exitcode
+                        ),
+                        WorkerTerminatedPrematurely
+                    )
                 # worker exited
                 util.debug('cleaning up worker %d' % i)
                 worker.join()