From 402ef120e19218544152502d1ea20709ff5adbc8 Mon Sep 17 00:00:00 2001
From: Bo-Yi Wu <appleboy.tw@gmail.com>
Date: Thu, 27 Sep 2018 08:59:44 +0800
Subject: [PATCH] fix: fmt output log to os.Stderr (#1571)

fix #1560 changes are breaking in App Engine.

cc @giulianobr @philippgille
---
 debug.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/debug.go b/debug.go
index 4fd23fa..c5e65b2 100644
--- a/debug.go
+++ b/debug.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"fmt"
 	"html/template"
+	"os"
 	"runtime"
 	"strconv"
 	"strings"
@@ -50,7 +51,7 @@ func debugPrintLoadTemplate(tmpl *template.Template) {
 
 func debugPrint(format string, values ...interface{}) {
 	if IsDebugging() {
-		fmt.Printf("[GIN-debug] "+format, values...)
+		fmt.Fprintf(os.Stderr, "[GIN-debug] "+format, values...)
 	}
 }