$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-psafont2-10318-28887/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-psafont2-10318-28887/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 85d9d40a1f3b28fb594530793774a02b5ef3c80a:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         85d9d40a1f3b28fb594530793774a02b5ef3c80a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 85d9d40 bump release for test build