diff -r ff72bd52d56a -r 9d2b2df2c2ba hgext/remotefilelog/contentstore.py
--- a/hgext/remotefilelog/contentstore.py	Fri Mar 06 10:52:44 2020 +0100
+++ b/hgext/remotefilelog/contentstore.py	Fri Mar 06 13:27:41 2020 -0500
@@ -300,7 +300,7 @@
 
         rl = self._revlog(name)
         ancestors = {}
-        missing = set((node,))
+        missing = {node}
         for ancrev in rl.ancestors([rl.rev(node)], inclusive=True):
             ancnode = rl.node(ancrev)
             missing.discard(ancnode)