title: How to install PHP extension 'pcntl' on my Mac OSX
body: <p>My operating system is:Mac OSX 10.11</p>
  
  <p>I'm trying to install Phabricator on my Mac, when I execute the command of </p>
  
  <pre><code>phabricator cpopt$ ./bin/phd start
  </code></pre>
  
  <p>I got an error:</p>
  
  <pre><code>"ERROR: The PHP extension 'pcntl' is not installed. You must install it to run daemons on this machine."
  </code></pre>
  
  <p>I've search this problem on google and I got lots of solutions,but they all don't work to me,I'm almost in despair.</p>
  
  <p>How can I achieve that?</p>
  
  <p><a href="https://i.stack.imgur.com/0fHvl.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/0fHvl.jpg" alt="enter image description here"></a></p>