报错：

Missing Signed-By in the sources.list

方案：

从提示信息可以看出sources.list文件缺少Signed-By字段

从文件系统中搜索gpg签名文件，选择合适的那个，我使用的是

Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg

参考：
https://www.cnblogs.com/bwcgq/p/18554260
https://blog.jackeylea.com/linux/how-to-fix-missing-signed-by-in-the-sources-list/
https://www.digitalocean.com/community/questions/n-missing-signed-by-in-the-sources-list-5-entry-for-http-mirrors-digitalocean-com-ubuntu
https://askubuntu.com/questions/1516700/missing-signed-by-in-the-sources-list5-entry-after-installing-ubuntu-24-04