apt - Fix GPG error
When doing an apt-get update to refresh index files from their sources, the indexes of available packages are fetched from the location(s) specified in /etc/apt/sources.list
Sometimes you will see an error like that:
debian:~# apt-get update Get:1 http://www.backports.org etch-backports Release.gpg [189B] Hit http://www.backports.org etch-backports Release ~ ~ (output shortened) ~ ~ Hit http://security.debian.org etch/updates/contrib Packages Hit http://security.debian.org etch/updates/main Sources Hit http://security.debian.org etch/updates/contrib Sources Fetched 180kB in 2s (75.2kB/s) Reading package lists... Done W: GPG error: http://www.backports.org etch-backports Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EA8E8B2116BA136C W: You may want to run apt-get update to correct these problems debian:~#
The error message is pretty understandable.
To resolve this problem, you only have to fetch the public key(s) from the mirror and execute apt-key add <keyfile>
debian:~# apt-key add archive.key OK
After adding the key, your update should work…