buf = xstrdup(v);
                argc = split_cmdline(buf, &argv);
                if (argc < 0)
-                       die("Bad branch.%s.mergeoptions string", branch);
+                       die("Bad branch.%s.mergeoptions string: %s", branch,
+                           split_cmdline_strerror(argc));
                argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
                memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
                argc++;
        opts.verbose_update = 1;
        opts.merge = 1;
        opts.fn = twoway_merge;
-       opts.msgs = get_porcelain_error_msgs();
+       opts.show_all_errors = 1;
+       set_porcelain_error_msgs(opts.msgs, "merge");
 
        trees[nr_trees] = parse_tree_indirect(head);
        if (!trees[nr_trees++])