sudo yum install centos-release-scl
sudo yum install devtoolset-$VERSION-gcc*
yum erase kernel-tools-libs kernel-tools kernel-headers
ln -s /opt/rh/devtoolset-9/root/usr/bin/gcc /bin/gcc
ln -s /opt/rh/devtoolset-9/root/usr/bin/cc /bin/cc
scl enable devtoolset-VERSION bash
which gcc
gcc --version