--- a/mercurial/upgrade.py	Fri Dec 08 23:48:23 2017 -0500
+++ b/mercurial/upgrade.py	Thu Dec 07 15:55:59 2017 +0100
@@ -259,7 +259,7 @@
 
 @registerformatvariant
 class removecldeltachain(formatvariant):
-    name = 'removecldeltachain'
+    name = 'plain-cl-delta'
 
     default = True