$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v9.0-u-ydi1-11367-29668/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v9.0-u-ydi1-11367-29668/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin bbb34557ffa9dabae4bb630d59fbee8575ea309f:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         bbb34557ffa9dabae4bb630d59fbee8575ea309f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bbb3455 bump release for test build