$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-abourgeois2-8868-27822/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-abourgeois2-8868-27822/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 38663a3b212b250b7be52dc9d6a98c2a8c606e76:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         38663a3b212b250b7be52dc9d6a98c2a8c606e76 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 38663a3 bump release for test build