How to remove the deprecation warnings in Symfony

问题:

The dreaded "is deprecated since version 2.6 and will be removed in 3.0" errors that Symfony is outputting all over the logs and console. I've followed all the guidelines I found that claim to solve it, including upgrading sensio/distribution-bundle and putting ~E_USER_DEPRECATED into php.ini

Still getting these messages spammed over me. Aside from some hard measures like forking Symfony or overwriting the trigger_error function, what am I missing?

php.ini:

error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT

bootstrap.php.cache:

namespace {
    error_reporting(error_reporting() & ~E_USER_DEPRECATED);
    $loader = require_once __DIR__.'/./autoload.php';
}