# php -n -dextension=phar.so -dextension=json.so -dextension=iconv.so composer.phar install
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 5 installs, 0 updates, 0 removals
  - Installing symfony/filesystem (dev-master df8e441): Cloning df8e441d07 from cache
  - Installing symfony/finder (dev-master d04fb01): Cloning d04fb01c1a from cache
  - Installing symfony/yaml (dev-master 066b3d0): Cloning 066b3d0b5e from cache
  - Installing psr/container (dev-master 2cc4a01): Cloning 2cc4a01788 from cache
  - Installing symfony/dependency-injection (dev-master 792c762): Cloning 792c762582 from cache
symfony/yaml suggests installing symfony/console (For validating YAML files using the lint command)
symfony/dependency-injection suggests installing symfony/expression-language (For using expressions in service container configuration)
symfony/dependency-injection suggests installing symfony/proxy-manager-bridge (Generate service proxies to lazy load them)
Writing lock file
Generating autoload files

# php -n -dextension=phar.so -dextension=json.so -dextension=iconv.so test.php

Fatal error: Uncaught Error: Class 'DOMDocument' not found in /mnt/c/checkouts/symfony/src/Symfony/Component/Config/Util/XmlUtils.php:52
Stack trace:
#0 /mnt/c/checkouts/symfony/src/Symfony/Component/Config/test.php(7): Symfony\Component\Config\Util\XmlUtils::loadFile('test.xml')
#1 {main}
  thrown in /mnt/c/checkouts/symfony/src/Symfony/Component/Config/Util/XmlUtils.php on line 52