--- a/mercurial/interfaces/repository.py	Sun Oct 06 23:36:51 2019 -0400
+++ b/mercurial/interfaces/repository.py	Sun Oct 06 23:36:51 2019 -0400
@@ -1547,6 +1547,10 @@
 
     names = interfaceutil.Attribute("""A ``namespaces`` instance.""")
 
+    filecopiesmode = interfaceutil.Attribute(
+        """The way files copies should be dealt with in this repo."""
+    )
+
     def close():
         """Close the handle on this repository."""