Bocs, itt a megoldás:

Running „apt-get update” with the version of apt in unstable will probably display the following (non-fatal) errors if you’re using unofficial apt sources:

W: GPG error: http://apt.example.com unstable Release: The following signatures
couldn’t be verified because the public key is not available:
NO_PUBKEY A35A4E6EF00175CA
W: You may want to run apt-get update to correct these problems

In order to fix this you need to import the key into gpg, then export the key into apt, using „apt-key”.

$ gpg –keyserver wwwkeys.eu.pgp.net –recv-keys A35A4E6EF00175CA
gpg: requesting key F00175CA from hkp server wwwkeys.eu.pgp.net
gpg: key F00175CA: public key „Sebastien NOEL ” imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg:              imported: 1
$ gpg –armor –export A35A4E6EF00175CA | sudo apt-key add –
gpg: no ultimately trusted keys found
OK

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