$ git clone -n https://src.fedoraproject.org/rpms/kf6-prison.git /var/lib/mock/f42-build-862104-170665/root/chroot_tmpdir/scmroot/kf6-prison
Cloning into '/var/lib/mock/f42-build-862104-170665/root/chroot_tmpdir/scmroot/kf6-prison'...
$ git fetch origin 4db9fc00e8ea162fdb56cfda7a656f7b1e409d74:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-prison
 * [new ref]         4db9fc00e8ea162fdb56cfda7a656f7b1e409d74 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4db9fc0 6.8.0