Installing gcc9 on CentOS 7

If you like to upgrade GCC to version 9 so you can a recent Python version like 3.14. You need to the following commands

1. Move to valut repo
   

   sed -i -e 's/mirror.centos.org/vault.centos.org/g' /etc/yum.repos.d/CentOS-*.repo
   sed -i -e 's/^#.*baseurl=http/baseurl=http/g' /etc/yum.repos.d/CentOS-*.repo
   sed -i -e 's/^mirrorlist=http/#mirrorlist=http/g' /etc/yum.repos.d/CentOS-*.repo
   sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/CentOS-*.repo
   sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/CentOS-*.repo
   sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/CentOS-*.repo
   sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/CentOS-SCLo-*.repo 2>/dev/null || true
   sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/CentOS-SCLo-*.repo 2>/dev/null || true
   sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/CentOS-SCLo-*.repo 2>/dev/null || true
   

2. Update Yum Caches
   

   yum clean all
   yum makecache
   

3. Install devtoolset-9
   

   yum install -y centos-release-scl
   yum install -y scl-utils devtoolset-9-gcc devtoolset-9-gcc-c++
   

4. Enable toolset
   

   scl enable devtoolset-9 bash
   

5. check the gcc version
   

   gcc --version