diff -r 8b3ad0252344 -r 10d15095d7c2 mercurial/windows.py
--- a/mercurial/windows.py	Mon Nov 21 15:38:56 2016 +0530
+++ b/mercurial/windows.py	Thu Oct 20 23:27:09 2016 +0900
@@ -171,7 +171,7 @@
             self.close()
             raise IOError(errno.EPIPE, 'Broken pipe')
 
-sys.__stdout__ = sys.stdout = winstdout(sys.stdout)
+sys.stdout = winstdout(sys.stdout)
 
 def _is_win_9x():
     '''return true if run on windows 95, 98 or me.'''