$ git clone -n https://src.fedoraproject.org/rpms/samba.git /var/lib/mock/f38-build-side-42-init-devel-604588-26233/root/chroot_tmpdir/scmroot/samba
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-604588-26233/root/chroot_tmpdir/scmroot/samba'...
$ git fetch origin b4c89569651d469675cea80315c53656a2a38aec:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/samba
 * [new ref]         b4c89569651d469675cea80315c53656a2a38aec -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4c8956 Update to version 4.18.2