Show curl error a bit better.

Signed-off-by: Junio C Hamano <junkio@cox.net>

http-fetch.c

@@ -1049,7 +1049,9 @@ static int fetch_object(struct alt_base *repo, unsigned char *sha1)
 	}
 
 	if (request->curl_result != CURLE_OK && request->http_code != 416) {
-		ret = error("%s", request->errorstr);
+		ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
+			    request->errorstr, request->curl_result,
+			    request->http_code, hex);
 		release_request(request);
 		return ret;
 	}