Add default case for disambiguation.

engine/lib/concrete_ident/concrete_ident.ml

@@ -269,8 +269,10 @@ module MakeToString (R : VIEW_RENDERER) = struct
                  methods which may be repeated (with their implementations),
                  and for fields (which are repeated by accessors). *)
             then
-              let path : View.ModPath.t = (View.of_def_id i.def_id).mod_path in
-              let path = List.map ~f:R.render_module path in
+              let mod_path : View.ModPath.t =
+                (View.of_def_id i.def_id).mod_path
+              in
+              let path = List.map ~f:R.render_module mod_path in
               (* Generates the list of all prefixes of reversed `path` *)
               List.folding_map ~init:[] (List.rev path) ~f:(fun acc chunk ->
                   let acc = chunk :: acc in
@@ -284,7 +286,9 @@ module MakeToString (R : VIEW_RENDERER) = struct
                          path (* This might shadow, we should escape *))
                  (* Find the shortest name that doesn't exist already *)
               |> List.find ~f:(Hash_set.mem name_set >> not)
-              |> Option.value_exn
+              |> Option.value
+                   ~default:
+                     (name ^ (View.ModPath.hash mod_path |> Int.to_string))
             else name
           in
           (* Update the maps and hashtables *)