Ubuntu 18.04 — 无人值守升级失败，错误代码为 404 Not Found

Question

为什么 Ubuntu 18.04 上的无人值守升级会出现 404 Not Found？

无人值守升级期间我收到 404 Not Found 错误。

这是包裹：http://security.ubuntu.com/ubuntu/pool/main/l/linux-meta-gcp/linux-gcp_5.0.0.1020.25_amd64.deb

然后我手动运行 wget，仍然遇到同样的问题：

获得http://security.ubuntu.com/ubuntu/pool/main/l/linux-meta-gcp/linux-gcp_5.0.0.1020.25_amd64.deb

给出：

http://security.ubuntu.com/ubuntu/pool/main/l/linux-meta-gcp/linux-gcp_5.0.0.1020.25_amd64.deb

Resolving security.ubuntu.com (security.ubuntu.com)... 91.189.88.24, 91.189.88.149, 91.189.88.173, ...
Connecting to security.ubuntu.com (security.ubuntu.com)|91.189.88.24|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
ERROR 404: Not Found.