title: ActiveJob and Sidekiq jobs stuck in enqueued
body: <p>So I just migrated to Rails 5.1.4 and I'm trying to make Active Job work, but the jobs are just stuck in the queue and never processed.</p>
  
  <ul>
  <li>rails: 5.1.4</li>
  <li>ruby: 2.4.3</li>
  <li>sidekiq: 5.0.5</li>
  <li>redis: 4.0.1</li>
  </ul>
  
  <p>sidekiq.yml</p>
  
  <pre><code>---
  :verbose: true
  :concurrency: 5
  :timeout: 60
  development:
    :concurrency: 25
  staging:
    :concurrency: 50
  production:
    :concurrency: 5
  :queues:
    - default
    - [high_priority, 2]
  </code></pre>
  
  <p>sidekiq.rb</p>
  
  <pre><code>Sidekiq.configure_server do |config|
    config.redis = {url: ENV['ACTIVE_JOB_URL'], network_timeout: 5}
  end
  
  Sidekiq.configure_client do |config|
    config.redis = {url: ENV['ACTIVE_JOB_URL'], network_timeout: 5}
  end
  </code></pre>
  
  <p>Here the is how I perform the task from the rails console:</p>
  
  <pre><code>TestJob.perform_later
  </code></pre>
  
  <p>TestJob.rb content:</p>
  
  <pre><code>class TestJob &lt; ApplicationJob
    queue_as :default
  
    def perform(*args)
      Rails.logger.debug "#{self.class.name}: I'm performing my job with arguments: #{args.inspect}"
    end
  end
  </code></pre>
  
  <p>The jobs are just stuck in the queue and never processed:</p>
  
  <p><a href="https://i.stack.imgur.com/N8v8o.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/N8v8o.png" alt="enter image description here"></a></p>