libstdc++.so.6: version `GLIBCXX_3.4.15′ not found Centos 6

You may come across this error (ie. old libstdc++) trying to compile Node 4.1.1 on CentOs 6 x64 after compiling gcc from source.  Here’s what to do to fix it (my version is 18 – u need at least 15):

1. Find the built libstdc++.so.6.0.18.so file
2. Relative to your gcc source root go to x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs/
3. Find libstdc++.so.6.0.18
4. Copy libstdc++.so.6.0.18 to /usr/lib64
5. Change the current symbolic link in the /usr/lib64 folder libstdc++.so and libstdc++.so.6 to point to the new version
6. rm [old symbolic links]
7. ln -s ./libstdc++.so.6.0.18 libstdc++.so
8. ln -s ./libstdc++.so.6.0.18 libstdc++.so.6