问题描述
每次我尝试执行软件更新时，我都会从软件管理器收到此错误：
W:GPG error: http://download.virtualbox.org/virtualbox/debian xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2F683C52980AECF, W:The repository 'http://download.virtualbox.org/virtualbox/debian xenial InRelease' is not signed., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., W:There is no public key available for the following key IDs:
A2F683C52980AECF , W:The repository 'http://ppa.launchpad.net/blackmage/f.lux/ubuntu xenial Release' does not have a Release file., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., W:The repository 'http://ppa.launchpad.net/gezakovacs/ppa/ubuntu xenial Release' does not have a Release file., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., W:The repository 'http://ppa.launchpad.net/zeal-developers/ppa/ubuntu xenial Release' does not have a Release file., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., W:http://deb.playonlinux.com/dists/trusty/InRelease: Signature by key 74F7358425EEB6176094C884E0F72778C4676186 uses weak digest algorithm (SHA1), W:http://liveusb.info/multisystem/depot/dists/all/Release.gpg: Signature by key 32027DE3D67157C45E69C0AE4E940D7FDD7FB8CC uses weak digest algorithm (SHA1), W:http://vagrant-deb.linestarve.com/dists/any/InRelease: Signature by key AD319E0F7CFFA38B4D9F6E55CE3F3DE92099F7A4 uses weak digest algorithm (SHA1), E:Failed to fetch http://ppa.launchpad.net/blackmage/f.lux/ubuntu/dists/xenial/main/source/Sources 404 Not Found, E:Failed to fetch http://ppa.launchpad.net/blackmage/f.lux/ubuntu/dists/xenial/main/binary-i386/Packages 404 Not Found, E:Failed to fetch http://ppa.launchpad.net/gezakovacs/ppa/ubuntu/dists/xenial/main/binary-i386/Packages 404 Not Found, E:Failed to fetch http://ppa.launchpad.net/zeal-developers/ppa/ubuntu/dists/xenial/main/source/Sources 404 Not Found, E:Failed to fetch http://ppa.launchpad.net/zeal-developers/ppa/ubuntu/dists/xenial/main/binary-i386/Packages 404 Not Found, E:Some index files failed to download. They have been ignored, or old ones used instead.
以下是我尝试编辑我拥有的存储库时所显示内容的一些屏幕截图：
我不确定如何解决这个问题。
最佳回答
显然，您在之前没有删除外部存储库的情况下进行了系统升级。解决问题的最简单方法是删除所有外部存储库并删除所有相关公钥。完成此操作后，更新存储库( sudo apt-get update )并检查现在是否一切都已修复……当不再发生错误时，您可以添加新的外部存储库，但请仔细检查这些存储库是否为 “matching Xenial” …
根据您添加的存储库，更新存储库时仍可能出现 “weak signature” 警告 – 但您可以忽略它，因为它只是一条信息性消息。
gpg: Signature by key ... uses weak digest algorithm (SHA1)
次佳回答
在 命令行 中输入以下内容：
wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox_2016.asc -O- | sudo apt-key add -
第三种回答
您需要删除升级前遗留的旧密钥。做：
sudo apt-key list
找到有问题的键(“virtualbox” 附近，”pub” 之后，xxx/KEYHERE)并执行：
sudo apt-key del KEYHERE
然后转到 https://www.virtualbox.org/wiki/Linux_Downloads 并按照“基于 Debian 的 Linux 发行版”中的说明进行操作