GnuPG isn't currently installed by the shellserver or devcserver role:
$ php phive.phar install phpdox Phive 0.9.0 - Copyright (C) 2015-2018 by Arne Blankerts, Sebastian Heuer and Contributors [ERROR] No executable gpg binary found. [ERROR] Either install gpg or enable the gnupg extension in PHP.
As an important piece of software, to check files integrity or for mail,
we really should add it to the shellserver base software list.