--- a/tests/test-rust-ancestor.py	Sat Oct 28 22:50:10 2023 +0200
+++ b/tests/test-rust-ancestor.py	Sun Oct 29 10:47:54 2023 +0100
@@ -157,7 +157,7 @@
         self.assertEqual(exc.args, ('InvalidRevision', wdirrev))
 
     def testheadrevs(self):
-        idx = self.parseindex()
+        idx = self.parserustindex()
         self.assertEqual(dagop.headrevs(idx, [1, 2, 3]), {3})