$ git clone -n https://github.com/xcp-ng-rpms/sm.git /var/lib/mock/v8.3-incoming-9040-27920/root/chroot_tmpdir/scmroot/sm
Cloning into '/var/lib/mock/v8.3-incoming-9040-27920/root/chroot_tmpdir/scmroot/sm'...
$ git fetch origin 17040a3ed901cd8a2d86392c4efe1627deddf906:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/sm
 * [new ref]         17040a3ed901cd8a2d86392c4efe1627deddf906 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 17040a3 Release 3.2.12-3.3