$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-10300-28869/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-10300-28869/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin ff114b898729b40931032a73e9100c0e28ed15ff:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         ff114b898729b40931032a73e9100c0e28ed15ff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff114b8 bump release for test build