尝试更新 18.04 时出错

Question

当我尝试更新到 Ubuntu 18.04 时，出现了以下问题：

W: GPG error: http://archive.canonical.com precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
E: The repository 'http://archive.canonical.com precise Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

请帮忙

Answer 1

我实际上是用错了存储库。删除它后，一切都正常了。

感谢@RoVo 的帮助:)

Answer 2

您需要添加公钥 40976EAF437D05B5：

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5