This is a clone of the original official gcc image repo: https://github.com/docker-library/gcc
The reason for this port is that the current official build is building on top of Debian Jessie, which is shipping with glibc 2.18, whereas I need to create portable binaries that will also run on redhat 7, which uses glibc 2.17. Building on centos 7 would result in binaries linked against glibc 2.17, which also run on glibc 2.18.
This image is currently building with centos 6 (EOL: Nov 30, 2020), which links against glibc 2.12.
Please refer to the documentation on the official image for gcc.