char *bad_hex = sha1_to_hex(current_bad_sha1);
        char *good_hex = join_sha1_array_hex(&good_revs, ' ');
 
-       fprintf(stderr, "Warning: the merge base between %s and [%s] "
+       warning("the merge base between %s and [%s] "
                "must be skipped.\n"
                "So we cannot be sure the first bad commit is "
                "between %s and %s.\n"
-               "We continue anyway.\n",
+               "We continue anyway.",
                bad_hex, good_hex, mb_hex, bad_hex);
        free(good_hex);
 }
 
                                 * check both source and destination
                                 */
                                if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
-                                       fprintf(stderr, "Warning: %s;"
-                                                       " will overwrite!\n",
-                                                       bad);
+                                       warning("%s; will overwrite!", bad);
                                        bad = NULL;
                                } else
                                        bad = "Cannot overwrite";
 
        process_http_object_request(freq);
 
        if (freq->http_code == 416) {
-               fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
+               warning("requested range invalid; we may already have all the data.");
        } else if (freq->curl_result != CURLE_OK) {
                if (stat(freq->tmpfile, &st) == 0)
                        if (st.st_size == 0)
 
        grep "merge base must be tested" my_bisect_log.txt &&
        grep $HASH4 my_bisect_log.txt &&
        git bisect skip > my_bisect_log.txt 2>&1 &&
-       grep "Warning" my_bisect_log.txt &&
+       grep "warning" my_bisect_log.txt &&
        grep $SIDE_HASH6 my_bisect_log.txt &&
        git bisect reset
 '