title: Build stuck due to background process in CircleCI
body: <p>I have the following build configuration in my <code>config.yml</code> file for CircleCI:</p>
  
  <pre><code>  - run:
        name: Start API
        command: |
          . dq/bin/activate
          python3 api/run.py
          background: true
  
    - run:
        name: Run Tests
        command: |
          . dq/bin/activate
          nose2 --plugin nose2.plugins.junitxml --junit-xml -v
  </code></pre>
  
  <p>Basically I want to start my API with the command <code>python3 api/run.py</code> so that I can run my test in the following steps (tests are sending http requests to the API).</p>
  
  <p>The <code>background: true</code> option does not seem to work as expected. The API starts but my build freezes and does not go to the following step.</p>
  
  <p>Am I doing anything wrong?</p>
  
  <p><a href="https://i.stack.imgur.com/KaHWz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KaHWz.png" alt="enter image description here"></a></p>
  
  <p>Note that I have also posted this question on CircleCI forum:
  <a href="https://discuss.circleci.com/t/running-flask-app-in-background/20022/2" rel="nofollow noreferrer">https://discuss.circleci.com/t/running-flask-app-in-background/20022/2</a></p>