--- a/mercurial/chgserver.py	Fri Aug 23 08:54:32 2019 -0700
+++ b/mercurial/chgserver.py	Wed Aug 28 17:36:53 2019 -0700
@@ -172,7 +172,7 @@
         except OSError:
             # could be ENOENT, EPERM etc. not fatal in any case
             pass
-    return _hashlist(map(trystat, paths))[:12]
+    return _hashlist(pycompat.maplist(trystat, paths))[:12]
 
 class hashstate(object):
     """a structure storing confighash, mtimehash, paths used for mtimehash"""