hi, after reading through this thread [1] i tried the following to build boost::program options: bjam define=_SECURE_SCL=0 define=_TESTING_SOMTHING=1 --toolset=msvc-8.0 --with-program_options variant=release to test the effect i added the folowing to the store function in program_options: #if _SECURE_SCL == 1 std::cout << "_SECURE_SCL == 1" << std::endl; #else std::cout << "_SECURE_SCL == 0" << std::endl; #endif #if _TESTING_SOMTHING == 1 std::cout << "_TESTING_SOMTHING == 1" << std::endl; #else std::cout << "_TESTING_SOMTHING == 0" << std::endl; #endif the strange thing now is, that _TESTING_SOMTHING is correctly set to 1 but _SECURE_SCL still is set to 1 and not to 0. did i miss something or is there another way to get this set properly to disable all runtime checks for release builds? [1] http://thread.gmane.org/gmane.comp.lib.boost.devel/143980/focus=144063 thx -chris -- Christopher Lux | | Bauhaus University Weimar | Faculty of Media - Virtual Reality Systems Group