Set the correct GNUPG environment, before you call gnupg_init()!
The current FPM/FastCGI/Module User must have read - if you import write - permissions on that directory. You won't get an error message, if something is not correct.
Without a correct environment, all other gnupg functions will not work as you expected.
<?php
putenv('GNUPGHOME=/var/www/vhosts/yourdomain/.gnupg');
error_reporting(E_ALL);
$res = gnupg_init();
gnupg_seterrormode($res,GNUPG_ERROR_WARNING);
$info = gnupg_keyinfo($res, 'your-key-id');
echo "Key - Info<pre>";
var_dump($info);
echo "</pre>";
?>
