--- a/mercurial/worker.py	Thu Jul 19 13:55:54 2018 -0400
+++ b/mercurial/worker.py	Thu Jul 19 21:36:24 2018 +0900
@@ -212,6 +212,7 @@
         signal.signal(signal.SIGINT, oldhandler)
         waitforworkers()
         signal.signal(signal.SIGCHLD, oldchldhandler)
+        selector.close()
         status = problem[0]
         if status:
             if status < 0: