diff -r 763d72925691 -r 3546a771e376 mercurial/obsolete.py
--- a/mercurial/obsolete.py	Wed May 17 22:33:15 2017 -0700
+++ b/mercurial/obsolete.py	Tue May 09 16:29:31 2017 -0700
@@ -1203,7 +1203,8 @@
     return divergent
 
 
-def createmarkers(repo, relations, flag=0, date=None, metadata=None):
+def createmarkers(repo, relations, flag=0, date=None, metadata=None,
+                  operation=None):
     """Add obsolete markers between changesets in a repo
 
     <relations> must be an iterable of (<old>, (<new>, ...)[,{metadata}])
@@ -1224,6 +1225,8 @@
         metadata = {}
     if 'user' not in metadata:
         metadata['user'] = repo.ui.username()
+    if operation:
+        metadata['operation'] = operation
     tr = repo.transaction('add-obsolescence-marker')
     try:
         markerargs = []