$ git clone -n https://src.fedoraproject.org/rpms/dnf.git /var/lib/mock/f40-build-2209155-52150/root/chroot_tmpdir/scmroot/dnf
Cloning into '/var/lib/mock/f40-build-2209155-52150/root/chroot_tmpdir/scmroot/dnf'...
$ git fetch origin dbc993d0e135bf622defa17c0bb7505547c43427:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dnf
 * [new ref]         dbc993d0e135bf622defa17c0bb7505547c43427 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dbc993d Update to 4.18.2