$ git clone -n https://src.fedoraproject.org/rpms/libtdb.git /var/lib/mock/f41-build-side-1-2812331-32939/root/chroot_tmpdir/scmroot/libtdb
Cloning into '/var/lib/mock/f41-build-side-1-2812331-32939/root/chroot_tmpdir/scmroot/libtdb'...
$ git fetch origin 9b390675cb9d55c30b7eaa6802258087ff068614:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtdb
 * [new ref]         9b390675cb9d55c30b7eaa6802258087ff068614 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9b39067 Reformat spec file