我目前正在尝试安装 libpq-dev 来安装 psycopg2。问题是，当我尝试安装它时，出现错误，提示我没有最新的 libpq5 版本。但是，当我尝试下载较新版本的 libpq5 时，系统说我已经有了最新版本。错误示例。
lhmendes@lhmendes-GA-78LMT-S2P:~$ sudo apt-get install libpq-dev
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:
libpq-dev : …