由于某种原因，我在尝试从 .deb 文件安装 libpng12-0 时遇到奇怪的错误。
命令：
dpkg -i libpng12-0_1.2.50-2+deb8u3_amd64.deb; apt-get install -f
错误：
Setting up apache2 (2.4.25-3+deb9u2) ...
info: Executing deferred 'a2enconf apache2-doc' for package apache2-doc
ERROR: Conf apache2-doc does not exist!
dpkg: error processing package apache2 (--configure): subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing: apache2
E: Sub-process /usr/bin/dpkg returned an error code (1)
apache2-doc 已安装（检查apt policy apache2-doc：）
我尝试安装的 .deb 文件：https://packages.debian.org/jessie/amd64/libpng12-0/download
答案1
清除并重新安装软件包，可能安装已损坏。
apt-get purge apache2-doc
apt-get install apache2-doc
dpkg -i libpng12-0_1.2.50-2+deb8u3_amd64.deb; apt-get install -f