$ git clone -n https://src.fedoraproject.org/rpms/kf6-prison.git /var/lib/mock/f42-build-side-1-3511152-46047/root/chroot_tmpdir/scmroot/kf6-prison
Cloning into '/var/lib/mock/f42-build-side-1-3511152-46047/root/chroot_tmpdir/scmroot/kf6-prison'...
$ git fetch origin a2eca3c45b06147aef288a93133e971136357325:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-prison
 * [new ref]         a2eca3c45b06147aef288a93133e971136357325 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a2eca3c 6.13.0