$ git clone -n https://github.com/xcp-ng-rpms/samba.git /var/lib/mock/v8.3-u-pcoval2-10162-28751/root/chroot_tmpdir/scmroot/samba
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10162-28751/root/chroot_tmpdir/scmroot/samba'...
$ git fetch origin f550bd062ca8de03a52a0eb4e2be5d3c174fee4f:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/samba
 * [new ref]         f550bd062ca8de03a52a0eb4e2be5d3c174fee4f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f550bd0 bump release for test build