$ git clone -n https://github.com/xcp-ng-rpms/kernel.git /var/lib/mock/v8.1-testing-2745-2160/root/chroot_tmpdir/scmroot/kernel
Cloning into '/var/lib/mock/v8.1-testing-2745-2160/root/chroot_tmpdir/scmroot/kernel'...
$ git reset --hard ef7a92a944364270a26aee1ec8eee293d1184da0
Downloading SOURCES/kernel-4.19.19.tar.gz (161 MB)
HEAD is now at ef7a92a Fix Release so that it's actually higher than the current official kernel