$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-asultanov2-9799-28516/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-asultanov2-9799-28516/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin aa5a8046fe074e0a26f6e920d691d8e8ba5a83a5:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         aa5a8046fe074e0a26f6e920d691d8e8ba5a83a5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aa5a804 bump release for test build