我的ubuntu没有正确更新
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://deb.playonlinux.com precise InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 73F0D6E88E3D6C3A W: Failed to fetch http://deb.playonlinux.com/dists/precise/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 73F0D6E88E3D6C3A W: Some index files failed to download. They have been ignored, or old ones used instead. 您应该添加“playonlinux”存储库的公钥：
wget -q "http://deb.playonlinux.com/public.gpg" -O- | sudo apt-key add -
之后运行：
sudo apt update
来自playonlinux下载页面。