$ git clone -n https://src.fedoraproject.org/rpms/kf6-kwindowsystem.git /var/lib/mock/f45-build-15113-468/root/chroot_tmpdir/scmroot/kf6-kwindowsystem
Cloning into '/var/lib/mock/f45-build-15113-468/root/chroot_tmpdir/scmroot/kf6-kwindowsystem'...
$ git fetch origin c5cf62f7c6b3d8e05b59a7a3a9b26c126bc4629a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kwindowsystem
 * [new ref]         c5cf62f7c6b3d8e05b59a7a3a9b26c126bc4629a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c5cf62f 6.31.0