$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-gtn2-9020-27915/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-gtn2-9020-27915/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin f3ac0c752cfbe8107b42b7dccd6941ebe0411573:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         f3ac0c752cfbe8107b42b7dccd6941ebe0411573 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f3ac0c7 bump release for test build