$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-asultanov1-9152-27973/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-asultanov1-9152-27973/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin bf5a51180f5c102623cb21693172a0180b2d9373:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         bf5a51180f5c102623cb21693172a0180b2d9373 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bf5a511 bump release for test build