let error_trace faulty = fprintf !dot_fmt "%a@." print_init_node faulty; print_pre (cedge_error ~to_init:true ()) !dot_fmt faulty; (* let prev = ref faulty.tag in *) List.iter (fun (_, _, s) -> print_pre (cedge_error ())!dot_fmt s; if s.kind = Node then fprintf !dot_fmt "%a@." (print_node_c config_error) s ) faulty.from