diff -r 649d3ac37a12 -r d783f945a701 mercurial/obsolete.py
--- a/mercurial/obsolete.py	Sun Oct 06 19:25:18 2019 -0400
+++ b/mercurial/obsolete.py	Mon Oct 07 00:04:04 2019 -0400
@@ -243,7 +243,7 @@
                 # if content cannot be translated to nodeid drop the data.
                 parents = None
 
-        metadata = tuple(sorted(metadata.iteritems()))
+        metadata = tuple(sorted(pycompat.iteritems(metadata)))
 
         yield (pre, sucs, flags, metadata, date, parents)
 
@@ -273,7 +273,7 @@
     """Return encoded metadata string to string mapping.
 
     Assume no ':' in key and no '\0' in both key and value."""
-    for key, value in meta.iteritems():
+    for key, value in pycompat.iteritems(meta):
         if b':' in key or b'\0' in key:
             raise ValueError(b"':' and '\0' are forbidden in metadata key'")
         if b'\0' in value:
@@ -644,7 +644,7 @@
                 r'in-marker cycle with %s' % pycompat.sysstr(node.hex(prec))
             )
 
-        metadata = tuple(sorted(metadata.iteritems()))
+        metadata = tuple(sorted(pycompat.iteritems(metadata)))
         for k, v in metadata:
             try:
                 # might be better to reject non-ASCII keys