title: Laravel horizon remains inactive after a new deploy
body: <p>We have Horizon running for quite some time now, and have no issues with it.
  But after our most recent deploy on production, it remains inactive and there are no workers being started.</p>
  
  <p>I fail to see the problem, nor do we get any errors logged into bugsnag, so I'm a bit lost here.</p>
  
  <p>What would be the best way to debug issues with Horizon?  I have verified, and I can talk to redis.  The dashboard also displays jobs on the queue, so it's just a matter of the workers not being started.</p>
  
  <p>We're setting up our instances using Laravel forge, and I can confirm that there is a daemon that runs php artisan horizon in the correct directory.  Running that command manually on the server also doesn't give me much info that I can work with.</p>
  
  <p>I'm sure here must be SOME error, but it's not beig caught / displayed / whatever.  Any thoughts on how to properly debug this?</p>
  
  <p>This is the contents of config/horizon.php:</p>
  
  <pre class="lang-php prettyprint-override"><code>&lt;?php
  
  return [
      'use' =&gt; 'default',
      'waits' =&gt; [
          'redis:default' =&gt; 60,
      ],
      'environments' =&gt; [
          'dev' =&gt; [
              'all-prio' =&gt; [
                  'connection' =&gt; 'redis',
                  'queue' =&gt; ['default', 'high', 'medium', 'low'],
                  'balance' =&gt; 'auto',
                  'processes' =&gt; 10,
                  'tries' =&gt; 3,
              ],
          ],
          'acc' =&gt; [
              'all-prio' =&gt; [
                  'connection' =&gt; 'redis',
                  'queue' =&gt; ['default', 'high', 'medium', 'low'],
                  'balance' =&gt; 'auto',
                  'processes' =&gt; 10,
                  'tries' =&gt; 3,
              ],
          ],
          'production' =&gt; [
              'high-prio' =&gt; [
                  'connection' =&gt; 'redis',
                  'queue' =&gt; ['high'],
                  'balance' =&gt; 'auto',
                  'processes' =&gt; 10,
                  'tries' =&gt; 5,
              ],
              'default-prio' =&gt; [
                  'connection' =&gt; 'redis',
                  'queue' =&gt; ['medium', 'default'],
                  'balance' =&gt; 'auto',
                  'processes' =&gt; 10,
                  'tries' =&gt; 3,
              ],
              'low-prio' =&gt; [
                  'connection' =&gt; 'redis',
                  'queue' =&gt; ['low'],
                  'balance' =&gt; 'auto',
                  'processes' =&gt; 5,
                  'tries' =&gt; 3,
              ],
          ],
      ],
  ];
  </code></pre>
  
  <p>The environment is correctly being set to 'production' on that environment.</p>
  
  <p>This is the contents of the config/database.php redis section:</p>
  
  <pre class="lang-php prettyprint-override"><code>    'redis' =&gt; [
          'cluster' =&gt; false,
          'default' =&gt; [
              'host' =&gt; env('REDIS_HOST', 'localhost'),
              'password' =&gt; env('REDIS_PASSWORD', null),
              'port' =&gt; env('REDIS_PORT', 6379),
              'database' =&gt; 0,
          ]
  </code></pre>