$NetBSD: patch-ag,v 1.3 2009/12/17 18:35:27 abs Exp $

--- unix/tclUnixPort.h.orig	2001-09-04 22:26:49.000000000 +0000
+++ unix/tclUnixPort.h
@@ -417,7 +417,9 @@ EXTERN int		gettimeofday _ANSI_ARGS_((st
  * isn't generally declared in a header file anywhere.
  */
 
+#ifndef errno
 extern int errno;
+#endif
 
 /*
  * Variables provided by the C library:
