title: Bundle install failed getting error occurred while installing unf_ext (0.0.6)
body: <p>I have tried running <code>bundle install</code> on my Mac but keep getting the following message:</p>
  
  <blockquote>
    <p><code>An error occurred while installing unf_ext (0.0.6), and Bundler cannot continue.</code><br>
    Make sure that <code>gem install unf_ext -v '0.0.6'</code> succeeds before bundling.</p>
  </blockquote>
  
  <p>But when I install <em>unf_ext(0.0.6)</em> I get an error message:</p>
  
  <pre><code>ERROR:  Error installing unf_ext:
  ERROR: Failed to build gem native extension.
  
  make install failed, exit code 2.
  </code></pre>
  
  <p>Any help would be appreciated,</p>
  
  <p>Thank you.</p>