apt-get install apt-source build-essential dpkg-dev
vi /etc/apt/sources.list
apt-get update
apt-get source xen-hypervisor-4.17-amd64
vi /etc/apt/sources.list
apt-get update
apt-get install debuild devscripts libzstd-dev ocaml checkpolicy
apt build-dep xen-hypervisor-4.14-amd64
cd xen-4.17.0+74-g3eac216e6e/
zcat ../xen-addons/xen-kconfig > debian/xen-kconfig
debuild -b -uc -us