$ sudo apt-get install openssh-serverReading package lists... DoneBuilding dependency tree       Reading state information... DoneSome packages could not be installed. This may mean that you haverequested an impossible situation or if you are using the unstabledistribution that some required packages have not yet been createdor been moved out of Incoming.The following information may help to resolve the situation:The following packages have unmet dependencies: openssh-server : Depends: openssh-client (= 1:5.9p1-5ubuntu1)                  Recommends: xauth but it is not going to be installed                  Recommends: ssh-import-id but it is not going to be installedE: Unable to correct problems, you have held broken packages.

有人说要卸载掉 openssh-client , 但是 openssh-client 被很多包依赖, 很多的 xserver 的包都依赖它, 这该怎么办好？

用 aptitude 仍然不行:

$ sudo aptitude install openssh-serverThe following NEW packages will be installed:  gcc-4.6-base:i386{a} libbsd0:i386{a} libc-bin:i386{ab} libc6:i386{ab} libcomerr2:i386{a} libedit2:i386{a}   libgcc1:i386{a} libgssapi-krb5-2:i386{ab} libk5crypto3:i386{ab} libkeyutils1:i386{a} libkrb5-3:i386{ab}   libkrb5support0:i386{ab} libselinux1:i386{a} libssl1.0.0:i386{ab} libtinfo5:i386{a} libx11-6:i386{ab} libxau6:i386{a}   libxcb1:i386{ab} libxdmcp6:i386{a} libxext6:i386{ab} libxmuu1:i386{a} openssh-client:i386{ab} openssh-server   ssh-import-id{a} xauth:i386{ab} zlib1g:i386{a} 0 packages upgraded, 26 newly installed, 0 to remove and 0 not upgraded.Need to get 9,157 kB of archives. After unpacking 24.0 MB will be used.The following packages have unmet dependencies: libkrb5-3 : Breaks: libkrb5-3:i386 (!= 1.10+dfsg~beta1-2ubuntu0.3) but 1.10+dfsg~beta1-2 is to be installed. libkrb5-3:i386 : Breaks: libkrb5-3 (!= 1.10+dfsg~beta1-2) but 1.10+dfsg~beta1-2ubuntu0.3 is installed. libk5crypto3 : Breaks: libk5crypto3:i386 (!= 1.10+dfsg~beta1-2ubuntu0.3) but 1.10+dfsg~beta1-2 is to be installed. libk5crypto3:i386 : Breaks: libk5crypto3 (!= 1.10+dfsg~beta1-2) but 1.10+dfsg~beta1-2ubuntu0.3 is installed. libc-bin : Conflicts: libc-bin:i386 but 2.15-0ubuntu10 is to be installed. libc-bin:i386 : Conflicts: libc-bin but 2.15-0ubuntu10.4 is installed. xauth : Conflicts: xauth:i386 but 1:1.0.6-1 is to be installed. xauth:i386 : Conflicts: xauth but 1:1.0.6-1 is installed. libxcb1 : Breaks: libxcb1:i386 (!= 1.8.1-1ubuntu0.2) but 1.8.1-1 is to be installed. libxcb1:i386 : Breaks: libxcb1 (!= 1.8.1-1) but 1.8.1-1ubuntu0.2 is installed. libkrb5support0 : Breaks: libkrb5support0:i386 (!= 1.10+dfsg~beta1-2ubuntu0.3) but 1.10+dfsg~beta1-2 is to be installed. libkrb5support0:i386 : Breaks: libkrb5support0 (!= 1.10+dfsg~beta1-2) but 1.10+dfsg~beta1-2ubuntu0.3 is installed. openssh-client : Conflicts: openssh-client:i386 but 1:5.9p1-5ubuntu1 is to be installed. openssh-client:i386 : Conflicts: openssh-client but 1:5.9p1-5ubuntu1.1 is installed. libx11-6 : Breaks: libx11-6:i386 (!= 2:1.4.99.1-0ubuntu2.1) but 2:1.4.99.1-0ubuntu2 is to be installed. libx11-6:i386 : Breaks: libx11-6 (!= 2:1.4.99.1-0ubuntu2) but 2:1.4.99.1-0ubuntu2.1 is installed. libgssapi-krb5-2 : Breaks: libgssapi-krb5-2:i386 (!= 1.10+dfsg~beta1-2ubuntu0.3) but 1.10+dfsg~beta1-2 is to be installed. libgssapi-krb5-2:i386 : Breaks: libgssapi-krb5-2 (!= 1.10+dfsg~beta1-2) but 1.10+dfsg~beta1-2ubuntu0.3 is installed. libc6 : Breaks: libc6:i386 (!= 2.15-0ubuntu10.4) but 2.15-0ubuntu10 is to be installed. libc6:i386 : Breaks: libc6 (!= 2.15-0ubuntu10) but 2.15-0ubuntu10.4 is installed. libxext6 : Breaks: libxext6:i386 (!= 2:1.3.0-3ubuntu0.1) but 2:1.3.0-3build1 is to be installed. libxext6:i386 : Breaks: libxext6 (!= 2:1.3.0-3build1) but 2:1.3.0-3ubuntu0.1 is installed. libssl1.0.0 : Breaks: libssl1.0.0:i386 (!= 1.0.1-4ubuntu5.10) but 1.0.1-4ubuntu5 is to be installed. libssl1.0.0:i386 : Breaks: libssl1.0.0 (!= 1.0.1-4ubuntu5) but 1.0.1-4ubuntu5.10 is installed.The following actions will resolve these dependencies:      Keep the following packages at their current version:1)      libbsd0:i386 [Not Installed]                       2)      libc-bin:i386 [Not Installed]                      3)      libc6:i386 [Not Installed]                         4)      libcomerr2:i386 [Not Installed]                    5)      libedit2:i386 [Not Installed]                      6)      libgcc1:i386 [Not Installed]                       7)      libgssapi-krb5-2:i386 [Not Installed]              8)      libk5crypto3:i386 [Not Installed]                  9)      libkeyutils1:i386 [Not Installed]                  10)     libkrb5-3:i386 [Not Installed]                     11)     libkrb5support0:i386 [Not Installed]               12)     libselinux1:i386 [Not Installed]                   13)     libssl1.0.0:i386 [Not Installed]                   14)     libtinfo5:i386 [Not Installed]                     15)     libx11-6:i386 [Not Installed]                      16)     libxau6:i386 [Not Installed]                       17)     libxcb1:i386 [Not Installed]                       18)     libxdmcp6:i386 [Not Installed]                     19)     libxext6:i386 [Not Installed]                      20)     libxmuu1:i386 [Not Installed]                      21)     openssh-client:i386 [Not Installed]                22)     openssh-server [Not Installed]                     23)     xauth:i386 [Not Installed]                         24)     zlib1g:i386 [Not Installed]                              Leave the following dependencies unresolved:         25)     ssh-import-id recommends openssh-server            Accept this solution? [Y/n/q/?] yNo packages will be installed, upgraded, or removed.0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.Need to get 0 B of archives. After unpacking 0 B will be used.

搞定, 先装一个依赖的指定版本的 openssh-client (旧版)：

sudo apt-get install openssh-client=1:5.9p1-5ubuntu1

然后再装 openssh-server 就OK了。