title: Activate virtualenv in Makefile
body: <p>How can I activate virtualenv in a Makefile?</p>
  
  <p><strong>I have tried:</strong></p>
  
  <pre><code>venv:
      @virtualenv venv
  
  active:
      @source venv/bin/activate
  </code></pre>
  
  <p><strong>And I've also tried:</strong></p>
  
  <pre><code>active:
      @. venv/bin/activate
  </code></pre>
  
  <p>and it doesn't activate virtualenv.</p>