$ git clone -n https://src.fedoraproject.org/rpms/dtk6gui.git /var/lib/mock/f41-build-837818-159407/root/chroot_tmpdir/scmroot/dtk6gui
Cloning into '/var/lib/mock/f41-build-837818-159407/root/chroot_tmpdir/scmroot/dtk6gui'...
$ git fetch origin b59a566036b7beef80a5fdc39166b6ea7f5f810b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dtk6gui
 * [new ref]         b59a566036b7beef80a5fdc39166b6ea7f5f810b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b59a566 6.0.18