diff -r 5dfb18b98a55 -r c3f6e97c71b1 hgext/obsolete.py
--- a/hgext/obsolete.py	Fri Jun 26 00:07:13 2015 -0700
+++ b/hgext/obsolete.py	Tue Jun 30 18:32:12 2015 -0700
@@ -48,7 +48,7 @@
     else:
         data = repo.opener.tryread('obsolete-relations')
         if not data:
-            data = repo.sopener.tryread('obsoletemarkers')
+            data = repo.svfs.tryread('obsoletemarkers')
         if data:
             raise util.Abort('old format of obsolete marker detected!\n'
                              'run `hg debugconvertobsolete` once.')
@@ -110,7 +110,7 @@
             except IOError:
                 pass
             ### second (json) format
-            data = repo.sopener.tryread('obsoletemarkers')
+            data = repo.svfs.tryread('obsoletemarkers')
             if data:
                 some = True
                 for oldmark in json.loads(data):