使用 better-dde 后，apt update 时提示

W: http://120.132.17.134:3000/better-dde/ppa/raw/branch/master/./InRelease: Key is stored in legacy trusted.gpg keyring (/etc/apt/trusted.gpg), see the DEPRECATION section in apt-key(8) for details.

原因是之前使用 apt-key 添加 key 的方式已经过时，需要将 key 放到 /etc/apt/trusted.gpg.d/ 中。better-dde 升级了 apt 版本，apt 给出这个警告。

这只是个警告，放着不管就可以，如果实在不想看到，解决方法也很简单：重新添加一遍 key 即可。例如我这里报的 4 个 warning，修复命令如下：

wget -q -O - http://120.132.17.134:3000/better-dde/ppa/raw/branch/master/better-dde.gpg | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/better-dde-keyring.gpg
wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/google-keyring.gpg
wget -q -O - https://mirrors.cloud.tencent.com/docker-ce/linux/debian/gpg | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/docker-keyring.gpg
wget -q -O - https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/microsoft-keyring.gpg