$ git clone -n https://github.com/xcp-ng-rpms/sm.git /var/lib/mock/v8.3-u-prebuild-9356-28114/root/chroot_tmpdir/scmroot/sm
Cloning into '/var/lib/mock/v8.3-u-prebuild-9356-28114/root/chroot_tmpdir/scmroot/sm'...
$ git fetch origin 6284cd9a5943b849f1ec1ec413b43d893daa7fe1:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/sm
 * [new ref]         6284cd9a5943b849f1ec1ec413b43d893daa7fe1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6284cd9 bump release for test build