我有一台运行 Ubuntu 18.04.6 LTS 的旧服务器，我怀疑有人试图安装或升级到错误的 Ubuntu 20.04 软件包，导致 apt 损坏和所谓的“Frankensystem”。
我想修复此问题，但又不想重新安装整个系统，尤其是服务器位于远程位置。是否可以逐个修复损坏的软件包？如果可以，我该怎么做？
以下是我遇到的错误：
运行时sudo apt update：
$ sudo apt update
Hit:1 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://archive.ubuntu.com/ubuntu focal-updates InRelease
Get:3 http://archive.ubuntu.com/ubuntu focal-backports InRelease [108 kB]
Get:4 http://archive.ubuntu.com/ubuntu focal-security InRelease [114 kB]
Fetched 222 kB in 2s (118 kB/s)
Traceback (most recent call last):
File "/usr/lib/cnf-update-db", line 8, in <module>
from CommandNotFound.db.creator import DbCreator
File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 11, in <module>
import apt_pkg
ImportError: libapt-pkg.so.6.0: cannot open shared object file: No such file or directory
Reading package lists... Done
E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/lib/command-not-found/ -a -e /usr/lib/cnf-update-db; then /usr/lib/cnf-update-db > /dev/null; fi'
E: Sub-process returned an error code
运行时sudo apt --fix-broken install：
$ sudo apt --fix-broken install
Reading package lists... Done
Building dependency tree... Done
Correcting dependencies... failed.
The following packages have unmet dependencies:
dirmngr : Depends: init-system-helpers (>= 1.52) but 1.51 is installed
gir1.2-gtk-3.0 : Depends: gir1.2-gdkpixbuf-2.0 (>= 2.40.0) but 2.36.11-2 is installed
Depends: gir1.2-pango-1.0 (>= 1.41.0) but 1.40.14-1ubuntu0.1 is installed
Depends: libgtk-3-0 (>= 3.24.7) but 3.22.30-1ubuntu4 is installed
gnupg : Depends: gpgv (>= 2.2.19-3ubuntu2.2) but 2.2.4-1ubuntu1.6 is installed
gnupg-utils : Depends: libreadline8 (>= 6.0) but it is not installed
gpg : Depends: libreadline8 (>= 6.0) but it is not installed
gpg-agent : Depends: init-system-helpers (>= 1.52) but 1.51 is installed
gpgconf : Depends: libreadline8 (>= 6.0) but it is not installed
gpgsm : Depends: libreadline8 (>= 6.0) but it is not installed
hplip : Depends: hplip-data (= 3.20.3+dfsg0-2) but 3.17.10+
当我检查时/usr/lib/x86_64-linux-gnu发现libapt-pkg.so.5.0存在，但是没有libapt-pkg.so.6.0
另外，/usr/lib/python3/dist-packages我发现apt_pkg.cpython-38-x86_64-linux-gnu.so这很奇怪，因为python3版本是3.6.9
关于备份，我找到了这些文件
/var/backups$ ls -l
total 7276
-rw-r--r-- 1 root root 153600 Apr 10 00:08 alternatives.tar.0
-rw-r--r-- 1 root root 9783 Jun 24 2022 alternatives.tar.1.gz
-rw-r--r-- 1 root root 9808 Nov 27 2021 alternatives.tar.2.gz
-rw-r--r-- 1 root root 9421 Mar 27 2021 alternatives.tar.3.gz
-rw-r--r-- 1 root root 6161 Mar 18 2021 alternatives.tar.4.gz
-rw-r--r-- 1 root root 6090 Jan 25 2021 alternatives.tar.5.gz
-rw-r--r-- 1 root root 6061 Nov 28 2020 alternatives.tar.6.gz
-rw-r--r-- 1 root root 154853 Apr 9 23:02 apt.extended_states.0
-rw-r--r-- 1 root root 12962 Apr 9 21:44 apt.extended_states.1.gz
-rw-r--r-- 1 root root 12828 Jul 26 2022 apt.extended_states.2.gz
-rw-r--r-- 1 root root 12821 Jul 4 2022 apt.extended_states.3.gz
-rw-r--r-- 1 root root 12806 Jun 23 2022 apt.extended_states.4.gz
-rw-r--r-- 1 root root 13304 Jun 17 2022 apt.extended_states.5.gz
-rw-r--r-- 1 root root 13269 Nov 26 2021 apt.extended_states.6.gz
-rw-r--r-- 1 root root 4649 Jun 23 2022 dpkg.diversions.0
-rw-r--r-- 1 root root 657 Jun 23 2022 dpkg.diversions.1.gz
-rw-r--r-- 1 root root 657 Jun 23 2022 dpkg.diversions.2.gz
-rw-r--r-- 1 root root 657 Jun 23 2022 dpkg.diversions.3.gz
-rw-r--r-- 1 root root 657 Jun 23 2022 dpkg.diversions.4.gz
-rw-r--r-- 1 root root 657 Jun 23 2022 dpkg.diversions.5.gz
-rw-r--r-- 1 root root 657 Jun 23 2022 dpkg.diversions.6.gz
-rw-r--r-- 1 root root 348 Mar 18 2021 dpkg.statoverride.0
-rw-r--r-- 1 root root 213 Mar 18 2021 dpkg.statoverride.1.gz
-rw-r--r-- 1 root root 213 Mar 18 2021 dpkg.statoverride.2.gz
-rw-r--r-- 1 root root 213 Mar 18 2021 dpkg.statoverride.3.gz
-rw-r--r-- 1 root root 213 Mar 18 2021 dpkg.statoverride.4.gz
-rw-r--r-- 1 root root 213 Mar 18 2021 dpkg.statoverride.5.gz
-rw-r--r-- 1 root root 213 Mar 18 2021 dpkg.statoverride.6.gz
-rw-r--r-- 1 root root 2529012 Jul 3 16:58 dpkg.status.0
-rw-r--r-- 1 root root 708160 Apr 10 00:09 dpkg.status.1.gz
-rw-r--r-- 1 root root 708160 Apr 10 00:09 dpkg.status.2.gz
-rw-r--r-- 1 root root 708160 Apr 10 00:09 dpkg.status.3.gz
-rw-r--r-- 1 root root 708160 Apr 10 00:09 dpkg.status.4.gz
-rw-r--r-- 1 root root 708160 Apr 10 00:09 dpkg.status.5.gz
-rw-r--r-- 1 root root 708160 Apr 10 00:09 dpkg.status.6.gz
-rw------- 1 root root 1336 Apr 9 22:33 group.bak
-rw------- 1 root shadow 1107 Apr 9 22:33 gshadow.bak
-rw------- 1 root root 3518 Apr 9 22:33 passwd.bak
-rw-r--r-- 1 root smmsp 64178 Mar 18 2021 sendmail.cf.bak
-rw-r--r-- 1 root smmsp 4058 Mar 18 2021 sendmail.mc.bak
-rw------- 1 root shadow 2479 Apr 9 22:33 shadow.bak
-rw-r--r-- 1 root smmsp 44618 Mar 18 2021 submit.cf.bak
-rw-r--r-- 1 root smmsp 2375 Mar 18 2021 submit.mc.bak
或者我可以使用这些文件中的任何一个将系统恢复到正常工作状态吗？