$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-asultanov2-9821-28532/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-asultanov2-9821-28532/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 99f08f89abab9ab28cd928bd50c1314333c6a097:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         99f08f89abab9ab28cd928bd50c1314333c6a097 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 99f08f8 bump release for test build