diff -r c701f616d852 -r 8d6164098782 rust/rhg/src/commands/debugdata.rs
--- a/rust/rhg/src/commands/debugdata.rs	Thu Dec 03 13:23:59 2020 -0800
+++ b/rust/rhg/src/commands/debugdata.rs	Mon Nov 30 19:34:49 2020 +0100
@@ -55,6 +55,15 @@
                 .into(),
             )),
         },
+        DebugDataErrorKind::AmbiguousPrefix => CommandError {
+            kind: CommandErrorKind::Abort(Some(
+                utf8_to_local(&format!(
+                    "abort: ambiguous revision identifier{}\n",
+                    rev
+                ))
+                .into(),
+            )),
+        },
         DebugDataErrorKind::UnsuportedRevlogVersion(version) => CommandError {
             kind: CommandErrorKind::Abort(Some(
                 utf8_to_local(&format!(