diff -r 649d3ac37a12 -r d783f945a701 mercurial/hook.py
--- a/mercurial/hook.py	Sun Oct 06 19:25:18 2019 -0400
+++ b/mercurial/hook.py	Mon Oct 07 00:04:04 2019 -0400
@@ -155,7 +155,7 @@
     env[b'HG_HOOKTYPE'] = htype
     env[b'HG_HOOKNAME'] = name
 
-    for k, v in args.iteritems():
+    for k, v in pycompat.iteritems(args):
         if callable(v):
             v = v()
         if isinstance(v, (dict, list)):