graph_name = get_commit_graph_filename(opts.obj_dir);
        open_ok = open_commit_graph(graph_name, &fd, &st);
-       if (!open_ok)
+       if (!open_ok && errno == ENOENT)
                return 0;
+       if (!open_ok)
+               die_errno(_("Could not open commit-graph '%s'"), graph_name);
        graph = load_commit_graph_one_fd_st(fd, &st);
        FREE_AND_NULL(graph_name);