https://sourceforge.net/p/xdb/bugs/38/
--- xbase64/xblock.cpp.orig	2010-10-02 22:57:35.000000000 +0200
+++ xbase64/xblock.cpp	2010-10-02 22:58:09.000000000 +0200
@@ -64,6 +64,7 @@
 
 //#include <stdio.h>
 //#include <stdlib.h>
+#include <errno.h>
 
 /*! \file xblock.cpp
 */