$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-psafont2-11524-29842/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-psafont2-11524-29842/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin c538b22cb22a29e901631566965cbf148f43bfb2:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         c538b22cb22a29e901631566965cbf148f43bfb2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c538b22 bump release for test build