While testing a Symfony web application in production environment (--env=prod) I encountered an odd exception which more or less was triggered with each request: Uncaught PHP Exception Symfony\Component\Debug\Exception\FatalErrorException: Compile Error: require(): Failed opening required 'var/cache/prod/doctrine/orm/Proxies/__CG__some-file.php' (include_path='.:/usr/share/php7:/usr/share/php') at vendor/doctrine/common/lib/Doctrine/Common/Proxy/AbstractProxyFactory.php line 223…