title: Symfony2 Shell.php error on production server
body: <p>I get the following error in <code>app_dev.php</code> on my production server:</p>
  
  <blockquote>
    <p>ErrorException: Notice: Undefined variable: output in /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Shell/Shell.php line 59</p>
    
    <ol>
    <li>in /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Shell/Shell.php
    line 59</li>
    <li>at ErrorHandler->handle('8', 'Undefined variable: output', '/www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Shell/Shell.php',
    '59', array('command' => 'find')) in
    /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Shell/Shell.php
    line 59</li>
    <li>at Shell->testCommand('find') in /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Adapter/AbstractFindAdapter.php
    line 123</li>
    <li>at AbstractFindAdapter->isSupported() in /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Adapter/GnuFindAdapter.php
    line 30</li>
    <li>at GnuFindAdapter->isSupported() in /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Finder.php
    line 700</li>
    <li>at Finder->searchInDirectory('/www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Validator/Resources/translations')
    in
    /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/Finder/Finder.php
    line 628</li>
    <li>at Finder->getIterator() in /www/acme/www/vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
    line 555</li>
    <li>at FrameworkExtension->registerTranslatorConfiguration(array('fallback'
    => 'pl', 'enabled' => true), object(ContainerBuilder)) in /www/acme/www/vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
    line 106</li>
    <li>at FrameworkExtension->load(array(array('translator' => array('fallback' => 'pl'), 'secret' =>
    'eea6ad638afadb62cd7bc360e98f7d3b', 'router' => array('resource' =>
    '/www/acme/www/app/config/routing.yml', 'strict_requirements' =>
    true), 'form' => true, 'csrf_protection' => true, 'validation' =>
    array('enable_annotations' => true), 'templating' => array('engines'
    => array('twig')), 'trust_proxy_headers' => false, 'default_locale' => 'pl', 'session' => null), array('router' => array('resource' =>
    '/www/acme/www/app/config/routing_dev.yml'), 'profiler' =>
    array('only_exceptions' => false))), object(ContainerBuilder)) in
    /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php
    line 42</li>
    <li>at MergeExtensionConfigurationPass->process(object(ContainerBuilder)) in
    /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/DependencyInjection/MergeExtensionConfigurationPass.php
    line 39</li>
    <li>at MergeExtensionConfigurationPass->process(object(ContainerBuilder)) in
    /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Compiler/Compiler.php
    line 119</li>
    <li>at Compiler->compile(object(ContainerBuilder)) in /www/acme/www/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
    line 494</li>
    <li>at ContainerBuilder->compile() in /www/acme/www/app/bootstrap.php.cache line 950</li>
    <li>at Kernel->buildContainer() in /www/acme/www/app/bootstrap.php.cache line 859</li>
    <li>at Kernel->initializeContainer() in /www/acme/www/app/bootstrap.php.cache line 571</li>
    <li>at Kernel->boot() in /www/acme/www/app/bootstrap.php.cache line 614</li>
    <li>at Kernel->handle(object(Request)) in /www/acme/www/web/app_dev.php line 29</li>
    </ol>
  </blockquote>
  
  <p>Everything works fine on my localhost so it can be something wrong with the server configuration.</p>