diff -r 23c9600607e7 -r 66357d4d03b2 hgext3rd/topic/compat.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hgext3rd/topic/compat.py	Sun Sep 10 22:41:54 2017 +0900
@@ -0,0 +1,24 @@
+# Copyright 2017 FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+"""
+Compatibility module
+"""
+from __future__ import absolute_import
+
+from mercurial import obsolete
+
+getmarkers = None
+successorssets = None
+try:
+    from mercurial import obsutil
+    getmarkers = getattr(obsutil, 'getmarkers', None)
+    successorssets = getattr(obsutil, 'successorssets', None)
+except ImportError:
+    pass
+
+if getmarkers is None:
+    getmarkers = obsolete.getmarkers
+if successorssets is None:
+    successorssets = obsolete.successorssets