diff -r 1c5cbf28f007 -r d524c88511a7 mercurial/pure/osutil.py
--- a/mercurial/pure/osutil.py	Sun Dec 18 02:08:59 2016 +0530
+++ b/mercurial/pure/osutil.py	Mon Dec 19 00:16:52 2016 +0530
@@ -159,7 +159,7 @@
 else:
     listdir = listdirpure
 
-if os.name != 'nt':
+if pycompat.osname != 'nt':
     posixfile = open
 
     _SCM_RIGHTS = 0x01