$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn1-10182-28769/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn1-10182-28769/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 1892cafe5262365f7e86761a2d001617bff43826:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         1892cafe5262365f7e86761a2d001617bff43826 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1892caf bump release for test build