I had to comment out the following to successfully setup and install Wordpress Multisite on a remote server. Not sure if I missed something, or if this should be added to the instructions @ https://roots.io/trellis/docs/multisite/. Otherwise I’m getting an error about “MULTISITE already defined”.
# trellis/roles/deploy/files/tmp_multisite_constants.php
<?php
error_reporting(E_ALL & ~E_NOTICE);
// define('MULTISITE', false);
// define('SUBDOMAIN_INSTALL', false);
define('WPMU_PLUGIN_DIR', null);
define('WP_PLUGIN_DIR', null);
define('WP_USE_THEMES', false);