enable_language(C) file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/main.c" "int main() { return 0;}") set(include_dir "${CMAKE_CURRENT_BINARY_DIR}/dir") set(default_include_dir "${CMAKE_CURRENT_BINARY_DIR}/dirDefault") file(MAKE_DIRECTORY "${include_dir}") file(MAKE_DIRECTORY "${default_include_dir}") add_executable(main "${CMAKE_CURRENT_BINARY_DIR}/main.c") include_directories("${include_dir}") target_include_directories(main AFTER PRIVATE "${default_include_dir}") get_target_property(actual_include_dirs main INCLUDE_DIRECTORIES) set(desired_include_dirs "${include_dir}" "${default_include_dir}") if (NOT "${actual_include_dirs}" MATCHES "${desired_include_dirs}") message(SEND_ERROR "include default does not work") endif()