ffi not enabled for Cygwin, for the moment.

source/texk/web2c/luatexdir/luaffi/ffi.h

@@ -151,6 +151,13 @@ static void (lua_remove)(lua_State *L, int idx) {
 #if (defined ARCH_X86 || defined ARCH_X64) && (defined OS_CE || defined OS_WIN || defined OS_LINUX || defined OS_BSD || defined OS_POSIX || defined OS_OSX)
 #define FFI_ENABLE_LUATEX_INTERFACE
 #endif 
+/* for the moment */
+#if (defined __CYGWIN__)
+#undef FFI_ENABLE_LUATEX_INTERFACE
+#endif 
+
+  
+
 
 #ifdef _WIN32