diff -r 21772a6a7861 -r 0e6ce6313e47 mercurial/worker.py
--- a/mercurial/worker.py	Thu Nov 10 16:49:42 2016 -0500
+++ b/mercurial/worker.py	Thu Nov 17 21:43:01 2016 +0900
@@ -102,6 +102,7 @@
             while True:
                 try:
                     p, st = os.waitpid(pid, (0 if blocking else os.WNOHANG))
+                    break
                 except OSError as e:
                     if e.errno == errno.EINTR:
                         continue