$ git clone -n https://src.fedoraproject.org/rpms/samba.git /var/lib/mock/f40-build-1936853-25145/root/chroot_tmpdir/scmroot/samba
Cloning into '/var/lib/mock/f40-build-1936853-25145/root/chroot_tmpdir/scmroot/samba'...
$ git fetch origin 4eeafad4ae263652aa41202255e6d51db0afc68b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/samba
 * [new ref]         4eeafad4ae263652aa41202255e6d51db0afc68b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4eeafad Update to version 4.20.4