title: Composer Fails to Install and Update
body: <p>I was doing the same thing in my server weeks ago, but now I can't. Here's my error output: </p>
  
  <blockquote>
    <p>composer install</p>
  </blockquote>
  
  <pre><code>Loading composer repositories with package information
  Installing dependencies (including require-dev)
  PHP Fatal error:  Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory' in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php:974
  Stack trace:
  #0 [internal function]: Composer\Util\ErrorHandler::handle(2, 'proc_open(): fo...', 'phar:///usr/loc...', 974, Array)
  #1 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(974): proc_open('stty -a | grep ...', Array, NULL, NULL, NULL, Array)
  #2 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(793): Symfony\Component\Console\Application-&gt;getSttyColumns()
  #3 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(754): Symfony\Component\Console\Application-&gt;getTerminalDimensions()
  #4 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(688): Symfony\Component\Console\Application-&gt;getTerminalWidth()
  #5 phar:///usr/local/bin/com in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php on line 974
  
  Fatal error: Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory' in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php:974
  Stack trace:
  #0 [internal function]: Composer\Util\ErrorHandler::handle(2, 'proc_open(): fo...', 'phar:///usr/loc...', 974, Array)
  #1 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(974): proc_open('stty -a | grep ...', Array, NULL, NULL, NULL, Array)
  #2 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(793): Symfony\Component\Console\Application-&gt;getSttyColumns()
  #3 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(754): Symfony\Component\Console\Application-&gt;getTerminalDimensions()
  #4 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(688): Symfony\Component\Console\Application-&gt;getTerminalWidth()
  #5 phar:///usr/local/bin/com in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php on line 974`
  </code></pre>