为什么安装openssh服务器会删除openssh客户机？

Question

在一台64位薄荷17.3肉桂机上，我面临以下情况：

$ sudo apt安装openssh-server

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  openssh-client:i386 openssh-sftp-server
Suggested packages:
  ssh-askpass:i386 libpam-ssh:i386 keychain:i386 monkeysphere:i386 rssh
  molly-guard monkeysphere
Recommended packages:
  ncurses-term ssh-import-id
The following packages will be REMOVED:
  openssh-client
The following NEW packages will be installed:
  openssh-client:i386 openssh-server openssh-sftp-server
0 upgraded, 3 newly installed, 1 to remove and 0 not upgraded.
Need to get 928 kB of archives.
After this operation, 1 418 kB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

我不明白它为什么要删除64位的openssh客户机，转而安装32位。

/etc/apt/sources.list

#deb cdrom:[Linux Mint 17.3 _Rosa_ - Release amd64 20151115]/ trusty contrib main non-free

/etc/apt/ folder .list.d文件夹包含许多PPA：

doublecmd.list
esmska.list
getdeb.list
google-chrome.list
graphics-drivers-ppa-trusty.list
inkscape_dev-stable-trusty.list
mono-xamarin.list
nijel-phpmyadmin-trusty.list
n-muench-programs-ppa2-trusty.list
official-package-repositories.list
official-source-repositories.list
ondrej-php-trusty.list
otto-kesselgulasch-gimp-trusty.list
playonlinux.list
spideroakone.list
spotify.list
steam.list
strukturag-libde265-trusty.list
ubuntu-sdk-team-ppa-trusty.list
ubuntu-touch-coreapps-drivers-daily-trusty.list
unit193-encryption-trusty.list
videolan-master-daily-trusty.list
virtualbox.list
wfg-0ad-trusty.list
wine.list

apt-获取更新

Reading package lists... Done  

我看不出任何错误。

apt -o Debug::pkgProblemResolver=true安装openssh-server

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
The following extra packages will be installed:
  openssh-client:i386 openssh-sftp-server
Suggested packages:
  ssh-askpass:i386 libpam-ssh:i386 keychain:i386 monkeysphere:i386 rssh
  molly-guard monkeysphere
Recommended packages:
  ncurses-term ssh-import-id
The following packages will be REMOVED:
  openssh-client
The following NEW packages will be installed:
  openssh-client:i386 openssh-server openssh-sftp-server
0 upgraded, 3 newly installed, 1 to remove and 0 not upgraded.
Need to get 928 kB of archives.
After this operation, 1,418 kB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort. 

apt缓存策略openssh-client openssh-server

openssh-client:
  Installed: 1:6.6p1-2ubuntu2.6
  Candidate: 1:6.6p1-2ubuntu2.6
  Version table:
 *** 1:6.6p1-2ubuntu2.6 0
        100 /var/lib/dpkg/status
     1:6.6p1-2ubuntu2.4 0
        500 http://archive.ubuntu.mirror.dkm.cz/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
     1:6.6p1-2ubuntu1 0
        500 http://archive.ubuntu.mirror.dkm.cz/ trusty/main amd64 Packages
openssh-server:
  Installed: (none)
  Candidate: 1:6.6p1-2ubuntu2.4
  Version table:
     1:6.6p1-2ubuntu2.4 0
        500 http://archive.ubuntu.mirror.dkm.cz/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
     1:6.6p1-2ubuntu1 0
        500 http://archive.ubuntu.mirror.dkm.cz/ trusty/main amd64 Packages

Answer 1

在您的apt-cache policy输出中，安装了openssh-client 1:6.6p1-2ubuntu2.6，但这与任何URL都不对应，版本号与服务器版本号不相同。

Debian包要求客户端和服务器版本完全匹配。

因此，很清楚为什么apt要删除您安装的amd64版本的openssh-client。不太清楚的是它为什么要安装i386版本的openssh-client。

所以，就这么做：

apt-get purge openssh-client

然后安装openssh-client和openssh-server。

apt-get install openssh-client openssh-server

PS:朱利安·安德烈斯·克劳德在#debian-apt上的解释。

juliank> faheem:它必须降低amd64版本的等级，这是被禁止的。但是，i 386 one显然被允许满足对其他体系结构的依赖(Multi-Arch: foreign)，因此它可以安装它。

满足对其他体系结构的依赖似乎有点古怪，但我认为i386客户端可能与amd64服务器一起工作。