post_upgrade() {

    # return if old pkgver >= 0.9.0-2
    [[ $(vercmp $2 0.9.0-2) -ge 0 ]] && return

    echo "---------------------------------------------------------------------
    stone-soup saves have moved to ~/.crawl.
    If you want to keep your old saves, move ~/.stone-soup to
    ~/.crawl.
---------------------------------------------------------------------"
}