--- /dev/null
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build arm arm64
+
+package os
+
+/*
+#cgo CFLAGS: -x objective-c
+#cgo LDFLAGS: -framework CoreFoundation -framework Foundation
+
+#include <sys/param.h>
+#include <CoreFoundation/CFString.h>
+#include <Foundation/NSPathUtilities.h>
+
+char tmpdir[MAXPATHLEN];
+
+char* loadtmpdir() {
+       tmpdir[0] = 0;
+       CFStringRef path = (CFStringRef)NSTemporaryDirectory();
+       CFStringGetCString(path, tmpdir, sizeof(tmpdir), kCFStringEncodingUTF8);
+       return tmpdir;
+}
+*/
+import "C"
+
+func init() {
+       if Getenv("TMPDIR") != "" {
+               return
+       }
+       dir := C.GoString(C.loadtmpdir())
+       if len(dir) == 0 {
+               return
+       }
+       if dir[len(dir)-1] == '/' {
+               dir = dir[:len(dir)-1]
+       }
+       Setenv("TMPDIR", dir)
+}