这是我在网上阅读论坛关于我的更新错误后删除 source.list.d 后得到的结果。最初它给出了 --add key...-- 错误。
$ sudo apt-get update
Reading package lists... Done
W: Unable to read /etc/apt/sources.list.d/ - DirectoryExists (2: No such file or directory)
W: Unable to read /etc/apt/sources.list - RealFileExists (2: No such file or directory)