psalm.xml

<?xml version="1.0"?>
<psalm
    errorLevel="2"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="https://getpsalm.org/schema/config"
    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
>
    <projectFiles>
        <directory name="src" />
        <ignoreFiles>
            <directory name="vendor" />
            <file name="src/Filesystem/FilesystemInterface.php" />
            <file name="src/Twig/Loader/LoaderInterface.php" />
        </ignoreFiles>
    </projectFiles>

    <issueHandlers>
        <DeprecatedInterface>
            <errorLevel type="suppress">
                <referencedClass name="Symfony\Component\Translation\TranslatorInterface" />
                <referencedClass name="Twig\Loader\ExistsLoaderInterface" />
            </errorLevel>
        </DeprecatedInterface>

        <DeprecatedClass>
            <errorLevel type="suppress">
                <referencedClass name="Symfony\Component\Translation\MessageSelector" />
            </errorLevel>
        </DeprecatedClass>

        <MissingReturnType>
            <errorLevel type="suppress">
                <file name="src/Filesystem/Filesystem.php" />
            </errorLevel>
        </MissingReturnType>

        <PossiblyNullReference>
            <errorLevel type="suppress">
                <file name="src/DependencyInjection/Configuration.php" />
            </errorLevel>
        </PossiblyNullReference>

        <UndefinedClass>
            <errorLevel type="suppress">
                <referencedClass name="Symfony\Component\Templating\TemplateReferenceInterface" />
                <referencedClass name="Symfony\Component\Translation\MessageSelector" />
            </errorLevel>
        </UndefinedClass>

        <UndefinedInterface>
            <errorLevel type="suppress">
                <referencedClass name="Symfony\Component\Templating\TemplateReferenceInterface" />
            </errorLevel>
        </UndefinedInterface>

        <UndefinedDocblockClass>
            <errorLevel type="suppress">
                <referencedClass name="Symfony\Component\Templating\TemplateReferenceInterface" />
                <referencedClass name="Symfony\Component\Translation\MessageSelector" />
            </errorLevel>
        </UndefinedDocblockClass>
    </issueHandlers>
</psalm>