--- a/rust/hg-cpython/src/cindex.rs	Fri Feb 07 16:03:35 2025 -0500
+++ b/rust/hg-cpython/src/cindex.rs	Fri Feb 07 16:07:35 2025 -0500
@@ -171,6 +171,9 @@
             Err(GraphError::ParentOutOfRange(rev)) => {
                 Err(vcsgraph::graph::GraphReadError::KeyedInvalidKey(rev.0))
             }
+            Err(GraphError::ParentOutOfOrder(_)) => {
+                Err(vcsgraph::graph::GraphReadError::InconsistentGraphData)
+            }
         }
     }
 }