AC_CHECK_LIB([pthread], [main],, AC_MSG_ERROR("required library 'pthread' is missing"))
AC_CHECK_LIB([udev], [main],, AC_MSG_ERROR("required library 'udev' is missing"))
AC_CHECK_LIB([pthread], [main],, AC_MSG_ERROR("required library 'pthread' is missing"))
AC_CHECK_LIB([udev], [main],, AC_MSG_ERROR("required library 'udev' is missing"))