Hello, I use linaro gcc 5.3 to compile cpp files using -std=gnu++14, and I got an link error: "/opt/arm-toolchain/linux/linaro/gcc-linaro-5.3-2016.02-x86_64_arm-linux-gnueabihf/bin/../lib/gcc/arm-linux-gnueabihf/5.3.1/../../../. ./arm-linux-gnueabihf/lib/libstdc++.so: undefined reference to `clock_gettime@GLIBC_2.17' I have read the man page that, clock_gettime is no longer exists until glibc 2.17, so, i removed clock_gettime from my own code, however, I still got such error from the compiler. but the compiler can compile some other projects ok. I hope somebody know how to resolve such problem. thanks all.