开发环境
（1）Ubuntu12.04
（2）openwrt 最新master
解决方法
找到/build_dir/host/bison-3.5.1/lib文件夹下的config.h和config.in.h
注释掉
/* Define to 1 if you have the `clock_gettime’ function. */
//#undef HAVE_CLOCK_GETTIME
/* Define to 1 if you have the `clock_settime’ function. */
//#undef HAVE_CLOCK_SETTIME
以及
/* Define to 1 if you have the `clock_gettime’ function. */
//#undef HAVE_CLOCK_GETTIME
/* Define to 1 if you have the `clock_settime’ function. */
//#undef HAVE_CLOCK_SETTIME
重新编译就可以了