title: Php Fatal error: momory size exhausted when using composer to install user-bundle
body: <p>When triing to install FOSuserbundle with composer I got the following message in the Terminal:<br>
   <strong>"PHP Fatal error:  Allowed memory size of 536870912 bytes exhausted (tried to allocate 79 bytes) in phar:///Users/myname/MyWebSite/composer.phar/src/Composer/ DependencyResolver/Solver.php on line 177"</strong></p>
  
  <p>How can I fix it? </p>
  
  <hr>
  
  <p>EDIT / FURTHER INFORMATION</p>
  
  <p>In Terminal typing: <strong>php -r "echo ini_get('memory_limit').PHP_EOL;"</strong><br>
  get me the following: <strong>128M</strong><br>
  while php.ini (App/MAMP/conf/php5.4.4/php.ini) has the following line:     <strong>memory_limit = 32M</strong></p>
  
  <p>why different value? 
  how can I change the value so that composer can install the bundle?</p>
  
  <p>I tried the following in terminal but got an error: <strong>php -d memory_limit=512M composer.phar/src/Composer/DependencyResolver/Solver.php</strong><br>
  error ==> <strong>Could not open input file: composer.phar/src/Composer/DependencyResolver/Solver.php</strong></p>