post_upgrade() {
    if [[ "$2" < "1.1.0.0" ]]; then
        echo
        echo "NOTE: This version of Bitcoin Unlimited follows the Bitcoin Cash (BCH) chain!"
        echo "See https://www.bitcoinunlimited.info/download for more information."
        echo "If you wish to stay on BTC chain, please use a different client!"
        echo
    fi
}