$ sudo apt-get update
获取:1 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye InRelease [113 kB]
忽略:2 http://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-updates InRelease
获取:3 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye-updates InRelease [36.8 kB]
获取:4 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye-backports InRelease [39.3 kB]
错误:5 http://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-updates Release
404 Not Found [IP: 101.6.15.130 80]
获取:6 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main Sources [8,612 kB]
获取:7 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main amd64 Packages [8,178 kB]
获取:8 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main Translation-zh [1,215 B]
获取:9 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main Translation-zh_CN [114 kB]
获取:10 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main Translation-en [6,241 kB]
获取:11 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main amd64 DEP-11 Metadata [4,049 kB]
获取:12 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main DEP-11 48x48 Icons [3,478 kB]
获取:13 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye/main DEP-11 64x64 Icons [7,315 kB]
获取:14 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye-backports/main amd64 Packages [56.8 kB]
获取:15 http://mirrors.tuna.tsinghua.edu.cn/debian bullseye-backports/main Translation-en [42.9 kB]
正在读取软件包列表... 完成
E: 仓库 “http://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-updates Release” 没有 Release 文件。
N: 无法安全地用该源进行更新，所以默认禁用该源。
N: 参见 apt-secure(8) 手册以了解仓库创建和用户配置方面的细节。
