复制？
在里面链接问题我已经发布了我的sources.list，它被认为没有什么不寻常的。那么我的问题怎么会是修复的重复呢sources.list？这有什么帮助呢？
原始问题：
我从他们的网站安装了 steam。Steam 想要安装一堆软件包，但因以下错误而停止：
Steam needs to install these additional packages:
libc6:amd64 libc6:i386 libegl1:amd64 libegl1:i386 libgbm1:amd64 libgbm1:i386 libgl1-mesa-dri:amd64 libgl1-mesa-dri:i386 libgl1:amd64 libgl1:i386 steam-libs-amd64:amd64 steam-libs-i386:i386
Press return to proceed with the installation:
......
Reading package lists... Done
Building dependency tree
Reading state information... Done
libegl1 is already the newest version (1.3.2-1~ubuntu0.20.04.1).
libegl1 set to manually installed.
libgbm1 is already the newest version (21.0.3-0ubuntu0.3~20.04.5).
libgbm1 set to manually installed.
libgl1 is already the newest version (1.3.2-1~ubuntu0.20.04.1).
libgl1 set to manually installed.
libgl1-mesa-dri is already the newest version (21.0.3-0ubuntu0.3~20.04.5).
libgl1-mesa-dri set to manually installed.
libc6 is already the newest version (2.31-0ubuntu9.3).
libc6 set to manually installed.
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:
libc6 : Breaks: libc6:i386 (!= 2.31-0ubuntu9.3) but 2.31-0ubuntu9.2 is to be installed
libc6:i386 : Breaks: libc6 (!= 2.31-0ubuntu9.2) but 2.31-0ubuntu9.3 is to be installed
E: Unable to correct problems, you have held broken packages.
手动安装 libc6-386 也不起作用：
$ sudo apt install libc6-i386
Reading package lists... Done
Building dependency tree
Reading state information... 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:
libc6-i386 : Depends: libc6 (= 2.31-0ubuntu9.2) but 2.31-0ubuntu9.3 is to be installed
E: Unable to correct problems, you have held broken packages.
更新：
$ apt policy libc6
libc6:
Installed: 2.31-0ubuntu9.3
Candidate: 2.31-0ubuntu9.3
Version table:
*** 2.31-0ubuntu9.3 100
100 /var/lib/dpkg/status
2.31-0ubuntu9.2 500
500 http://mx.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
2.31-0ubuntu9 500
500 http://mx.archive.ubuntu.com/ubuntu focal/main amd64 Packages
$ apt policy libc6-i386
libc6-i386:
Installed: (none)
Candidate: 2.31-0ubuntu9.2
Version table:
2.31-0ubuntu9.2 500
500 http://mx.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
2.31-0ubuntu9 500
500 http://mx.archive.ubuntu.com/ubuntu focal/main amd64 Packages
答案1
N0rbert 的评论让我走上了正确的轨道，但它仍然想删除相当多的软件包：
$ sudo aptitude install libc6=2.31-0ubuntu9.2
The following packages will be DOWNGRADED:
libc6
0 packages upgraded, 0 newly installed, 1 downgraded, 0 to remove and 14 not upgraded.
Need to get 2 715 kB of archives. After unpacking 0 B will be used.
The following packages have unmet dependencies:
libc6-dbg : Depends: libc6 (= 2.31-0ubuntu9.3) but 2.31-0ubuntu9.2 is to be installed
libc6-dev : Depends: libc6 (= 2.31-0ubuntu9.3) but 2.31-0ubuntu9.2 is to be installed
The following actions will resolve these dependencies:
Remove the following packages:
1) build-essential [12.8ubuntu1.1 (focal-updates, now)]
2) g++ [4:9.3.0-1ubuntu2 (focal, now)]
3) g++-9 [9.3.0-17ubuntu1~20.04 (focal-security, focal-updates, now)]
4) libboost-atomic1.71-dev [1.71.0-6ubuntu6 (focal, now)]
5) libboost-chrono1.71-dev [1.71.0-6ubuntu6 (focal, now)]
6) libboost-date-time1.71-dev [1.71.0-6ubuntu6 (focal, now)]
7) libboost-filesystem-dev [1.71.0.0ubuntu2 (focal, now)]
8) libboost-filesystem1.71-dev [1.71.0-6ubuntu6 (focal, now)]
9) libboost-regex-dev [1.71.0.0ubuntu2 (focal, now)]
10) libboost-regex1.71-dev [1.71.0-6ubuntu6 (focal, now)]
11) libboost-serialization1.71-dev [1.71.0-6ubuntu6 (focal, now)]
12) libboost-system1.71-dev [1.71.0-6ubuntu6 (focal, now)]
13) libboost-thread-dev [1.71.0.0ubuntu2 (focal, now)]
14) libboost-thread1.71-dev [1.71.0-6ubuntu6 (focal, now)]
15) libboost1.71-dev [1.71.0-6ubuntu6 (focal, now)]
16) libc6-dbg [2.31-0ubuntu9.3 (now)]
17) libc6-dev [2.31-0ubuntu9.3 (now)]
18) libexpat1-dev [2.2.9-1build1 (focal, now)]
19) libfreetype-dev [2.10.1-2ubuntu0.1 (focal-security, focal-updates, now)]
20) libfreetype6-dev [2.10.1-2ubuntu0.1 (focal-security, focal-updates, now)]
21) libicu-dev [66.1-2ubuntu2.1 (focal-security, focal-updates, now)]
22) libjpeg-dev [8c-2ubuntu8 (focal, now)]
23) libjpeg-turbo8-dev [2.0.3-0ubuntu1.20.04.1 (focal-security, focal-updates, now)]
24) libjpeg8-dev [8c-2ubuntu8 (focal, now)]
25) libncurses-dev [6.2-0ubuntu2 (focal, now)]
26) libpng-dev [1.6.37-2 (focal, now)]
27) libpython3-dev [3.8.2-0ubuntu2 (focal, now)]
28) libpython3.8-dev [3.8.10-0ubuntu1~20.04.1 (focal-security, focal-updates, now)]
29) libstdc++-9-dev [9.3.0-17ubuntu1~20.04 (focal-security, focal-updates, now)]
30) libtiff-dev [4.1.0+git191117-2ubuntu0.20.04.2 (focal-security, focal-updates, now)]
31) python3-dev [3.8.2-0ubuntu2 (focal, now)]
32) python3.8-dev [3.8.10-0ubuntu1~20.04.1 (focal-security, focal-updates, now)]
33) zlib1g-dev [1:1.2.11.dfsg-2ubuntu1.2 (focal-updates, now)]
Leave the following dependencies unresolved:
34) dpkg-dev recommends build-essential
35) gcc recommends libc6-dev | libc-dev
36) cython3 recommends python3-dev
37) gcc-9 recommends libc6-dev (>= 2.13-0ubuntu6)
38) gdb recommends libc-dbg
39) libgcc-9-dev recommends libc6-dev (>= 2.13-0ubuntu6)
40) libpython3.8-dev recommends libc6-dev | libc-dev
41) python3.8-dev recommends libc6-dev | libc-dev
42) python3-pip recommends build-essential
43) python3-pip recommends python3-dev (>= 3.2)
2.31-0ubuntu9.2因此我强制libc6-dev并且libc6-dbg：
$ sudo aptitude install libc6=2.31-0ubuntu9.2 libc6-dev=2.31-0ubuntu9.2 libc6-dbg=2.31-0ubuntu9.2
此命令运行顺利。Steam 现在可以正常工作。
libc6=2.31-0ubuntu9.3但还有一个问题：我怎么把事情搞砸了？我当初是怎么想的？我应该为此提出一个新问题吗？