I maintained a sysroot with glibc 2.17 (it was 2.12 before when there are still CentOS 6 presence), built with latest GCC, for $DAYJOB. You can then use whateve

I maintained a sysroot with glibc 2.17 (it was 2.12 before when there are still CentOS 6 presence), built with latest GCC, for $DAYJOB. You can then use whatever modern toolchain you like (be it Clang+LLD or latest GCC+binutils), just point sysroot to it. Runs everywhere, don't need a container with old distro. Wasn't too bad, but definitely takes ~0.2 SDE to maintain.