die("unable to read blob object %s", sha1_to_hex(sha1));
 
        strcpy(path, ".merge_file_XXXXXX");
-       fd = mkstemp(path);
-       if (fd < 0)
-               die("unable to create temp-file");
+       fd = xmkstemp(path);
        if (write_in_full(fd, buf, size) != size)
                die("unable to write temp-file");
        close(fd);