diff -up ./src/libdar/secu_string.cpp.orig ./src/libdar/secu_string.cpp
--- ./src/libdar/secu_string.cpp.orig	2012-12-25 17:45:46.876345801 +0000
+++ ./src/libdar/secu_string.cpp	2012-12-25 17:47:03.439168451 +0000
@@ -23,6 +23,8 @@
 /*********************************************************************/
 //
 
+#include <unistd.h>
+
 #include "../my_config.h"
 
 extern "C"