diff -r 2959c3e986e0 -r bd872f64a8ba hgext/histedit.py
--- a/hgext/histedit.py	Sat May 06 04:51:25 2017 +0530
+++ b/hgext/histedit.py	Fri Feb 10 16:56:29 2017 -0800
@@ -1641,8 +1641,8 @@
     if os.path.exists(os.path.join(repo.path, 'histedit-state')):
         state = histeditstate(repo)
         state.read()
-        histedit_nodes = set([action.node for action
-                             in state.actions if action.node])
+        histedit_nodes = {action.node for action
+                          in state.actions if action.node}
         common_nodes = histedit_nodes & set(nodelist)
         if common_nodes:
             raise error.Abort(_("histedit in progress, can't strip %s")