gpg --keyserver keyserver.ubuntu.com --recv-keys 68980A0EA10B4DE8
gpg -a --export 68980A0EA10B4DE8 | sudo apt-key add -
Fetched 841 kB in 28s (29.3 kB/s)
W: GPG error: http://packages.mate-desktop.org raring Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 68980A0EA10B4DE8
W: Failed to fetch http://ppa.launchpad.net/pmcenery/ppa/ubuntu/dists/raring/main/binary-i386/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
userx@bw:~$
Como faço para corrigir isso?
Como faço para adicionar um PUBKEY para obter arquivos necessários para concluir a instalação do Cinnamon?
gpg --keyserver keyserver.ubuntu.com --recv-keys 68980A0EA10B4DE8
gpg -a --export 68980A0EA10B4DE8 | sudo apt-key add -