apt-get安装dh-systemd失败，原因是debhelper，但debhelper已经是最新版本

Question

我正在运行Ubuntu 16.04。我想安装dh-systemd包。当我尝试使用apt-get执行此操作时，出现以下错误：

  sudo apt-get -f install dh-systemd
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:
 dh-systemd : Depends: debhelper but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

但据apt-get报道，debhelper是最新版本：

 sudo apt-get -f install debhelper
Reading package lists... Done
Building dependency tree       
Reading state information... Done
debhelper is already the newest version (10.2.2ubuntu1~ubuntu16.04.1).
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

我已经尝试了apt-get update和apt-get upgrade，但是这些错误还没有被清除。我也尝试了AskUbuntu上推荐的-f install，--configure -a，-f install序列，但还是没有成功。任何帮助都将不胜感激！

Answer 1

我删除了debhelper，然后安装了dh-systemd和debhelper，从而实现了这一点

sudo apt-get remove debhelper
sudo apt-get install dh-systemd
sudo apt-get install debhelper -t xenial-backports

(第二步安装了dh-systemd和debhelper，最后一步升级了debhelper和dh-systemd，以及其他一些软件包)。