mercurial/repository.py

--- a/mercurial/repository.py	Mon Aug 27 10:15:15 2018 -0700
+++ b/mercurial/repository.py	Wed Aug 15 16:50:44 2018 +0000
@@ -991,6 +991,12 @@
 class imanifeststorage(interfaceutil.Interface):
     """Storage interface for manifest data."""
 
+    tree = interfaceutil.Attribute(
+        """The path to the directory this manifest tracks.
+
+        The empty bytestring represents the root manifest.
+        """)
+
     index = interfaceutil.Attribute(
         """An ``ifilerevisionssequence`` instance.""")