title: composer install/update failed
body: <p>Anyone has experience with this error:</p>
  
  <pre><code>[301.7MB/151.72s] The following exception is caused by a lack of memory or swap, or not having swap configured
  [301.7MB/151.72s] Check https://getcomposer.org/doc/articles/troubleshooting.md#proc-open-fork-failed-errors for details
  
  
  Warning: proc_open(): fork failed - Cannot allocate memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 979
  
    [ErrorException]
    proc_open(): fork failed - Cannot allocate memory
  </code></pre>
  
  <p>I already set the memory limit to 768M to 1024M and have swap more than enough around 4GB but still experience this problem.</p>
  
  <pre><code>free -m
                total        used        free      shared  buff/cache   available
  Mem:           4184        1877         823         177        1482        1808
  Swap:          5023         596        4427
  </code></pre>
  
  <p>.</p>
  
  <pre><code>php -r "echo ini_get('memory_limit').PHP_EOL;"
  768M
  </code></pre>
  
  <p>Or even set the memory limit manually:</p>
  
  <pre><code>php -d extension=phar.so -d extension=xmlwriter.so -dmemory_limit=1024M /usr/local/bin/composer.phar --profile -vvv update
  </code></pre>