$NetBSD: patch-ae,v 1.2 2005/11/05 03:27:56 rillig Exp $

--- unix/tkUnixPort.h.orig	2001-10-13 01:25:10.000000000 +0000
+++ unix/tkUnixPort.h
@@ -123,8 +123,10 @@
  * Not all systems declare the errno variable in errno.h. so this
  * file does it explicitly.
  */
-
+#include <errno.h>
+#ifndef errno
 extern int errno;
+#endif
 
 /*
  * Define "NBBY" (number of bits per byte) if it's not already defined.