我原本是 Ubuntu 14，后来升级到了 16，但在安装、等过程中出现了一些问题apt update。upgrade计算机现在可以正常工作，但仍然存在一些小问题，有时取决于我尝试安装的软件包。
问题是，我现在应该正在使用 Ubuntu 16.04（“关于这台计算机”就是这么显示的），但如果我输入tty1，例如，我会得到这个：
Ubuntu 16.04.6 LTS ......
(login)
Welcome to Ubuntu 18.04.3 LTS ....
Documentation
..
0 packages can be updated
...
...
New release '18.04.2 LTS' available.
Run do-release-upgrade to upgrade it
这非常令人困惑。关于我遇到的一些问题，例如，我在尝试执行应用程序时收到此错误：
error while loading shared libraries: libmysqlclient.so.18: cannot open shared object file: No such file or directory`
所以我使用apt-file search并发现我需要libmysqlclient-dev，但这是我尝试安装包时得到的结果：
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:
libmysqlclient-dev : Depends: zlib1g-dev but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
我可以尝试什么来解决这些问题吗？