报错：

root@ecs-BoaVC:~# apt-get update
Get:1 http://security.debian.org/debian-security buster/updates InRelease [34.8 kB]
Get:2 http://deb.debian.org/debian buster InRelease [122 kB]               
Get:3 http://deb.debian.org/debian buster-updates InRelease [56.6 kB]
Reading package lists... Done       
E: Repository 'http://security.debian.org/debian-security buster/updates InRelease' changed its 'Suite' value from 'stable' to 'oldoldstable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.3' to '10.13'
E: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Suite' value from 'stable' to 'oldoldstable'N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
E: Repository 'http://deb.debian.org/debian buster-updates InRelease' changed its 'Suite' value from 'stable-updates' to 'oldoldstable-updates'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

解决方案如下：

apt-get update --allow-releaseinfo-change

即可看到：

root@ecs-BoaVC:~# apt-get update --allow-releaseinfo-change
Get:1 http://security.debian.org/debian-security buster/updates InRelease [34.8 kB]
Get:2 http://deb.debian.org/debian buster InRelease [122 kB]
Get:3 http://deb.debian.org/debian buster-updates InRelease [56.6 kB]
Get:4 http://security.debian.org/debian-security buster/updates/main Sources [422 kB]
Get:5 http://deb.debian.org/debian buster/main Sources [7852 kB]
Get:6 http://security.debian.org/debian-security buster/updates/main amd64 Packages [550 kB]
Get:7 http://security.debian.org/debian-security buster/updates/main Translation-en [297 kB]
Get:8 http://deb.debian.org/debian buster-updates/main Sources.diff/Index [12.1 kB]
Ign:8 http://deb.debian.org/debian buster-updates/main Sources.diff/Index
Get:9 http://deb.debian.org/debian buster-updates/main amd64 Packages.diff/Index [12.1 kB]
Ign:9 http://deb.debian.org/debian buster-updates/main amd64 Packages.diff/Index
Get:10 http://deb.debian.org/debian buster-updates/main Translation-en.diff/Index [6148 B]
Ign:10 http://deb.debian.org/debian buster-updates/main Translation-en.diff/Index
Get:11 http://deb.debian.org/debian buster/main amd64 Packages [7909 kB]
Get:12 http://deb.debian.org/debian buster/main Translation-en [5969 kB]
Get:13 http://deb.debian.org/debian buster-updates/main Sources [4616 B]
Get:14 http://deb.debian.org/debian buster-updates/main amd64 Packages [8788 B]
Get:15 http://deb.debian.org/debian buster-updates/main Translation-en [6915 B]
Fetched 23.1 MB in 1min 7s (342 kB/s)
Reading package lists… Done
N: Repository 'http://security.debian.org/debian-security buster/updates InRelease' changed its 'Suite' value from 'stable' to 'oldoldstable'
N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.3' to '10.13'
N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Suite' value from 'stable' to 'oldoldstable'N: Repository 'http://deb.debian.org/debian buster-updates InRelease' changed its 'Suite' value from 'stable-updates' to 'oldoldstable-updates'