Media change: please insert the disc labeled

• 执行命令：

sudo apt install gcc

• 具体错误

Media change: please insert the disc labeled
 'Ubuntu 20.04.4 LTS _Focal Fossa_ - Release amd64 (20220223)'
in the drive '/cdrom/' and press [Enter]

• 解决办法

/etc/apt/sources.list文件，注释掉cdrom一行，例如：

# deb cdrom:[Ubuntu 20.04.4 LTS _Focal Fossa_ - Release amd64 (20220223)]/ focal main restricted

• 再次执行命令，成功