diff -r 7a5d6e2fd2d5 -r 47de34f79f93 mercurial/worker.py
--- a/mercurial/worker.py	Thu Jul 28 20:49:57 2016 +0100
+++ b/mercurial/worker.py	Thu Jul 28 20:51:20 2016 +0100
@@ -98,8 +98,8 @@
                 if err.errno != errno.ESRCH:
                     raise
     def waitforworkers():
-        for _pid in pids:
-            st = _exitstatus(os.wait()[1])
+        for pid in pids:
+            st = _exitstatus(os.waitpid(pid, 0)[1])
             if st and not problem[0]:
                 problem[0] = st
                 killworkers()