VyOS runs on a custom Linux Kernel (which is 4.19) at the time of this writing. This repository holds a Jenkins Pipeline which is used to build the Custom Kernel (x86_64/amd64 at the moment) and all required out-of tree modules.
This repositories content has been moved to: https://github.com/vyos/vyos-build/tree/current/packages/frr as part of https://phabricator.vyos.net/T2625