struct rev_info rev;
        struct commit *commit;
        struct strbuf format = STRBUF_INIT;
-       struct object_id junk_oid;
        const char *head;
        struct pretty_print_context pctx = {0};
        struct strbuf author_ident = STRBUF_INIT;
        rev.diffopt.break_opt = 0;
        diff_setup_done(&rev.diffopt);
 
-       head = resolve_ref_unsafe("HEAD", 0, junk_oid.hash, NULL);
+       head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
        if (!strcmp(head, "HEAD"))
                head = _("detached HEAD");
        else