Debian install

Trying to install as explained in your installation on Debian and Ubuntu.
I had to install before that : curl, dirmngr, apt-transport-https

while installing I get the error :
gpg: keyserver receive failed: Server indicated a failure.
W: GPG-fout: crystal InRelease: De volgende ondertekeningen konden niet geverifieerd worden omdat de publieke sleutel niet beschikbaar is: NO_PUBKEY 09617FD37CC06B54
W: De pakketbron ‘ crystal InRelease’ is niet ondertekend.
N: Gegevens uit een dergelijke pakketbron kunnen niet geauthenticeerd worden en ze gebruiken houdt daarom een potentieel gevaar in.
N: Zie de man-pagina apt-secure(8) voor details over het aanmaken van een pakketbron en over de configuratie langs gebruikerskant.

Is this normal ? aptitude update gives the same error.
When executing aptitude install crystal I get a security warning, but installation took place. Not ensuring…

Hi @wannes,

It’s not clear to me if you did follow the instructions listed at .

That should add the signing key.

curl -sSL | sudo bash

  The above line is the one I used from the url you mention.

Besides the security message, everything works fine.

kind regards,


The error is that the key is not available at the keyserver gpg: keyserver receive failed: Server indicated a failure. We need to switch to hosting the pubkey elsewhere.

There seems to be 2 problems that can happen there.

First is that there was apparently some bug in gpg:

Sometimes gpg has problems downloading keys from remote server, it might be better to work with gpg2 if it’s available for your system. However it has been reported that gpg2 in version 2.1.17 is also affected by such issue. We recommend you to downgrade or upgrade it to a newer version.

Another thing that I had to do was:

In the file: /home/YOU/.gnupg/dirmngr.conf
add the line:

This seems to be a different issue with DNS handling if you are on a network with IPv6 addresses.

In general it does seem to work for most people.

GPG keyservers have never been reliable, the install script needs to be changed to not rely on them

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