$ git clone -n https://github.com/xcp-ng-rpms/sm.git /var/lib/mock/v8.3-v-qcow2-9851-28564/root/chroot_tmpdir/scmroot/sm
Cloning into '/var/lib/mock/v8.3-v-qcow2-9851-28564/root/chroot_tmpdir/scmroot/sm'...
$ git fetch origin 8a03ab9c42deb1c45e5e59b43875d4f161cd8409:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/sm
 * [new ref]         8a03ab9c42deb1c45e5e59b43875d4f161cd8409 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a03ab9 Release 3.2.12-16.1.0.qcow2.1