--- a/hgext3rd/evolve/__init__.py	Tue Mar 07 13:31:19 2017 +0100
+++ b/hgext3rd/evolve/__init__.py	Tue Mar 07 09:47:37 2017 -0800
@@ -1502,7 +1502,7 @@
         # XXX This is a terrible terrible hack, please get rid of it.
         lock = repo.wlock()
         try:
-            repo.opener.write('graftstate', orig.hex() + '\n')
+            repo.vfs.write('graftstate', orig.hex() + '\n')
             try:
                 graftcmd = commands.table['graft'][0]
                 ret = graftcmd(ui, repo, old_obsolete=True, **{'continue': True})
@@ -1716,7 +1716,7 @@
                 tmpctx = repo[tmpid]
                 obsolete.createmarkers(repo, [(bumped, (tmpctx,))])
         except MergeFailure:
-            repo.opener.write('graftstate', bumped.hex() + '\n')
+            repo.vfs.write('graftstate', bumped.hex() + '\n')
             repo.ui.write_err(_('evolution failed!\n'))
             msg = _("fix conflict and run 'hg evolve --continue'\n")
             repo.ui.write_err(msg)
@@ -3043,7 +3043,7 @@
         lock = repo.lock()
         if kwargs.get('old_obsolete'):
             if kwargs.get('continue'):
-                obsoleted.extend(repo.opener.read('graftstate').splitlines())
+                obsoleted.extend(repo.vfs.read('graftstate').splitlines())
             else:
                 obsoleted.extend(revs)
         # convert obsolete target into revs to avoid alias joke

--- a/hgext3rd/evolve/legacy.py	Tue Mar 07 13:31:19 2017 +0100
+++ b/hgext3rd/evolve/legacy.py	Tue Mar 07 09:47:37 2017 -0800
@@ -51,7 +51,7 @@
         if 'debugc' in arg:
             break
     else:
-        data = repo.opener.tryread('obsolete-relations')
+        data = repo.vfs.tryread('obsolete-relations')
         if not data:
             data = repo.svfs.tryread('obsoletemarkers')
         if data:
@@ -90,7 +90,7 @@
             store = repo.obsstore
             ### very first format
             try:
-                f = repo.opener('obsolete-relations')
+                f = repo.vfs('obsolete-relations')
                 try:
                     some = True
                     for line in f: