- if exists_path node parent edges then (
- let loc = loc_of_node data in
- failwithf "%a: adding %s creates a dependency cycle"
- Ast.string_loc loc (string_of_node data)
+ (match exists_path node parent edges with
+ | None -> ()
+ | Some nodes ->
+ let loc = loc_of_node data in
+ failwithf "%a: dependency cycle: %s -> %s"
+ Ast.string_loc loc
+ (String.concat " -> " (List.map string_of_node nodes))
+ (string_of_node data)