GPG Error on preliminary stable stretch builds

Hi TDE friends, I am installing the new Debian Stretch on my computer, with preliminary stable builds repo. When i try to download the GPG key, i get this error : root@nibelheim:/home/dobigeon# apt-key adv --keyserver keys.gnupg.net --recv-key A04BE668 Executing: /tmp/apt-key-gpghome.MwJokQaOGB/gpg.1.sh --keyserver keys.gnupg.net --recv-key A04BE668 gpg: failed to start the dirmngr '/usr/bin/dirmngr': Aucun fichier ou dossier de ce type gpg: connecting dirmngr at '/tmp/apt-key-gpghome.MwJokQaOGB/S.dirmngr' failed: Aucun fichier ou dossier de ce type gpg: keyserver receive failed: Pas de dirmngr A problem with the GPG key ? Or the command line on the wiki page ( https://wiki.trinitydesktop.org/Preliminary_Stable_Builds ) ? Thanks for your help.