title: Problem installing PEAR package with GMP extension requirement
body: <p>I want to install the Crypt_DiffieHellman PEAR package, that gives me the following error:</p>
  
  <pre><code>pear/Crypt_DiffieHellman requires PHP extension "gmp"
  </code></pre>
  
  <p>So I installed the gmp extension (using MacPorts' "php5-gmp"), both <code>php -m</code> and <code>extension_loaded('gmp')</code> indicate that the extension is loaded. However I still get the PEAR error when I try to install the package.</p>
  
  <p>Am I missing something here? Or is this a (known) bug with the package/PEAR installer?  </p>