$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-asultanov2-9234-28020/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-asultanov2-9234-28020/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 6fba868c79fa928fd3e5e8383163d2637cc76d57:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         6fba868c79fa928fd3e5e8383163d2637cc76d57 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6fba868 bump release for test build