Patch by Stanislav Maslovski <stanislav.maslovski@gmail.com>.
See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=488491

--- tcl8.5-8.5.8.orig/generic/tclPort.h
+++ tcl8.5-8.5.8/generic/tclPort.h
@@ -24,7 +24,7 @@
 #if defined(__WIN32__)
 #   include "tclWinPort.h"
 #else
-#   include "tclUnixPort.h"
+#   include "../unix/tclUnixPort.h"
 #endif
 
 #if !defined(LLONG_MIN)