一、操作和错误发现

在sudo apt update ；sudo apt upgrade时，出现错误提示：

dpkg : Breaks: libapt-pkg5.0 (< 1.7~b) but 1.6.15 is to be installed
E: Broken packages

二、错误分析1

sudo apt-get install aptitude时

报下面的错误：

The following packages have unmet dependencies:
 dpkg : Breaks: libapt-pkg5.0 (< 1.7~b) but 1.6.15 is to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
解决过程：我使用的linux 的CodeName 是groovy 

[email protected]:~$ lsb_release -a 
No LSB modules are available.
Distributor ID:    Ubuntu
Description:    Ubuntu 20.10
Release:    20.10
Codename:    groovy

在下面的源中都不含有groovy的CodeName 源：
https://mirrors.aliyun.com/ubuntu/dists
https://mirrors.huaweicloud.com/ubuntu/dists
https://mirrors.tuna.tsinghua.edu.cn/ubuntu/dists

比如《阿里》的 https://mirrors.aliyun.com/ubuntu/dists的源如下：

这样，你能知道，你的ubuntu是否在该镜像中被支持， 上面的groovy就没有支持。

使用这些源中的groovy时直接报错"Not Found"，因为这些源中都不含有groovy

在https://mirrors.163.com/ubuntu/dists中的groovy就是一个空壳。一开始使用了163中的groovy。然而在sudo apt-get update就失败了，同样报错“Not Found”。换了163中的bionic源，update就能成功。然而安装 aptitude时，依然报错，查了好久无意看到有人建议使用focal源，然后“sudo apt-get install aptitude”就成功了。最后用了mirrors.aliyun.com 中的focal源。所以，在预先下载Ubuntu的时候，就需要考虑源是否被支持。

二、另一个错误

        还是因为以上原因，可能将老版Ubuntu的组件安装进来，在sudo apt-get upgrade时， 碰到另外一个错误，如下：

(base) [email protected]:~$ sudo apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 distro-info-data : Breaks: distro-info (< 0.20~) but 0.18ubuntu0.18.04.1 is to be installed
 dpkg : Breaks: libapt-pkg5.0 (< 1.7~b) but 1.6.14 is to be installed
E: Broken packages

解决办法：

sudo apt remove ubuntu-advantage-tools

然后就可以了。