diff -r 40861b2254a5 -r 4237398c67c0 mercurial/configitems.py
--- a/mercurial/configitems.py	Fri Jun 30 03:44:07 2017 +0200
+++ b/mercurial/configitems.py	Fri Jun 30 03:44:08 2017 +0200
@@ -119,6 +119,9 @@
 coreconfigitem('server', 'bundle1gd',
     default=None,
 )
+coreconfigitem('server', 'compressionengines',
+    default=list,
+)
 coreconfigitem('ui', 'clonebundleprefers',
     default=list,
 )