尝试在新的 Ubuntu 18.04 上安装python3-dev并使用：libssl-dev
$ sudo apt install libssl-dev python3-dev
但我得到了以下错误：
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:
libssl-dev : Depends: libssl1.1 (= 1.1.0g-2ubuntu4) but 1.1.1-1ubuntu2.1~18.04.4 is to be installed
Recommends: libssl-doc but it is not going to be installed
python3-dev : Depends: python3 (= 3.6.5-3) but 3.6.7-1~18.04 is to be installed
Depends: libpython3-dev (= 3.6.5-3) but it is not going to be installed
Depends: python3.6-dev (>= 3.6.5-2~) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
什么原因可能导致该问题？如何解决？