1.更新系统:

sudo apt update && sudo apt upgrade

2.安装 gcc-8-base 包:

sudo apt install gcc-8-base

3.打开 /etc/apt/sources.list，注释所有的 buster 仓库，在行的开头加上 #。在文件的末尾添加以下几行:

deb http://deb.debian.org/debian bullseye main contrib non-free
deb http://deb.debian.org/debian bullseye-updates main contrib non-free
deb http://security.debian.org/debian-security bullseye-security main
deb http://ftp.debian.org/debian bullseye-backports main contrib non-free

4.更新列表:

sudo apt update

5.运行升级命令:

sudo apt full-upgrade

跳出选择窗口，选"Y"

6.重启系统:

systemctl reboot

7.重启后清理不必要的软件包:

sudo apt --purge autoremove

8.内核升级:

apt update -y && apt dist-upgrade -y