diff -up widelands-build17-src/src/main.cc.includes widelands-build17-src/src/main.cc
--- widelands-build17-src/src/main.cc.includes	2012-04-23 11:46:49.000000000 +0200
+++ widelands-build17-src/src/main.cc	2012-06-25 14:10:48.344023268 +0200
@@ -29,6 +29,9 @@
 #include <stdexcept>
 #include <typeinfo>
 
+// fork, setsid, close, dup
+#include <unistd.h>
+
 #include <SDL_main.h>
 
 #ifndef WIN32