nonvalidroute.xml

<?xml version="1.0" encoding="UTF-8" ?>

<routes xmlns="http://symfony.com/schema/routing"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/routing https://symfony.com/schema/routing/routing-1.0.xsd">

    <route id="blog_show" path="/blog/{slug}">
        <default key="_controller">MyBundle:Blog:show</default>
        <option key="compiler_class">RouteCompiler</option>
        <foo key="bar">baz</foo>
    </route>
</routes>