$ git clone -n https://github.com/xcp-ng-rpms/kernel.git /var/lib/mock/v8.3-u-qcasasnovas1-10272-28849/root/chroot_tmpdir/scmroot/kernel
Cloning into '/var/lib/mock/v8.3-u-qcasasnovas1-10272-28849/root/chroot_tmpdir/scmroot/kernel'...
$ git fetch origin 20ad59ce2f6fbd6317b9d8c9d56b6c4ae54b4fa7:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/kernel
 * [new ref]             20ad59ce2f6fbd6317b9d8c9d56b6c4ae54b4fa7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 20ad59ce2 bump release for test build