1.apt update && apt upgrade
2.snapd報錯無法更新需移除snapd
添加exit 0的命令到/var/lib/dpkg/info/snapd.prerm，然後運行以下命令。
dpkg --purge --force-all snapd
apt-get install snapd
apt update && apt upgrade
3.再執行do-release-upgrade進行安裝即可。
4.執行lsb_release -a命令確認
root@notes:/home/notes# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.2 LTS
Release: 18.04
Codename: bionic