$ git clone -n https://github.com/xcp-ng-rpms/sm.git /var/lib/mock/v8.3-incoming-11274-29620/root/chroot_tmpdir/scmroot/sm
Cloning into '/var/lib/mock/v8.3-incoming-11274-29620/root/chroot_tmpdir/scmroot/sm'...
$ git fetch origin 8954ddc7bb386422e37e059668ef9801e5854ad7:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/sm
 * [new ref]         8954ddc7bb386422e37e059668ef9801e5854ad7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8954ddc QCOW2 release on 3.2.12-17.2