$ git clone -n https://github.com/xcp-ng-rpms/xapi /var/lib/mock/v8.3-u-psafont1-10491-29050/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-psafont1-10491-29050/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 681575dc7761b982c0c7bf34b86ca1a3a69b634c:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         681575dc7761b982c0c7bf34b86ca1a3a69b634c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 681575d bump release for test build