我的真正目标是运行 systemd-journal-remote，以便我可以将日志从该设备发送到远程日志接收器。apt-get 更新/升级显示没有需要升级的软件包
$ sudo apt-get install systemd-journal-remote
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:
systemd-journal-remote : Depends: systemd (= 232-25+deb9u4) but 232-25+deb9u2 is to be installed
E: Unable to correct problems, you have held broken packages.
$ sudo apt-get install systemd
Reading package lists... Done
Building dependency tree
Reading state information... Done
systemd is already the newest version (232-25+deb9u2).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$ cat /etc/issue
Raspbian GNU/Linux 9 \n \l
$ cat /etc/debian_version
9.4
答案1
我找到了原因。检查 /etc/apt/preferences.d 中以“.pref”结尾的文件。在我的例子中，我有一个名为 10-somefilename.pref 的文件，它保存了我所有的软件包的初始版本。