diff -r 948fac24bc39 -r 8c66a680f396 mercurial/manifest.py
--- a/mercurial/manifest.py	Thu Apr 02 13:04:41 2020 -0400
+++ b/mercurial/manifest.py	Mon Feb 03 22:17:19 2020 -0500
@@ -760,6 +760,7 @@
 _noop = lambda s: None
 
 
+@interfaceutil.implementer(repository.imanifestdict)
 class treemanifest(object):
     def __init__(self, dir=b'', text=b''):
         self._dir = dir