小编Whe*_*rdy的帖子

我正在尝试使用 apt-get 从第三方存储库安装特定版本的 redis-server，它在 apt-cache 策略中列出，但无法安装。例如：

$ apt-cache policy redis-server
redis-server:
  Installed: (none)
  Candidate: 2:2.8.19-1chl1~trusty1
  Version table:
     2:2.8.19-1chl1~trusty1 0
        500 http://ppa.launchpad.net/chris-lea/redis-server/ubuntu/ trusty/main amd64 Packages
     2:2.8.4-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

$ apt-get install redis-server=2.8.19-1chl1~trusty1
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Version '2.8.19-1chl1~trusty1' for 'redis-server' was not found

如果我尝试安装 redis-server 而不选择软件包版本，它会尝试安装我尝试指定的版本：

$ apt-get -s install redis-server
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed: …