mercurial/configitems.py

--- a/mercurial/configitems.py	Wed Sep 20 02:40:25 2017 +0530
+++ b/mercurial/configitems.py	Fri Sep 15 10:42:49 2017 -0700
@@ -191,7 +191,7 @@
     alias=[('experimental', 'evolution.bundle-obsmarker')],
 )
 coreconfigitem('experimental', 'stabilization.track-operation',
-    default=False,
+    default=True,
     alias=[('experimental', 'evolution.track-operation')]
 )
 coreconfigitem('experimental', 'exportableenviron',