What causes "Named arguments are not supported for %s "%s"." in twigphp/Twig?

Use only positional arguments for this function/filter/test.

twigphp/Twig · error · SyntaxError

Named arguments are not supported for

Error message

Named arguments are not supported for %s "%s".

What it means

When a Twig callable (function/filter/test) has no underlying PHP callable, extractArguments() cannot map named arguments to parameters. If the template nevertheless passes named arguments, a SyntaxError is thrown stating that named arguments are unsupported for that callable. This protects against silently ignoring named options.

Solutions

Use only positional arguments for this function/filter/test.
Register a real PHP callable for the Twig callable if named arguments should be supported.
Wrap the call in a custom Twig function whose callable signature exposes the parameters you want to name.

Example fix

{# before #}
{{ dump(var=values) }}
{# after #}
{{ dump(values) }}

Defensive patterns

Strategy: validation

Try / catch

try {
    $html = $twig->render($template, $ctx);
} catch (Twig\Error\SyntaxError $e) {
    if (str_contains($e->getMessage(), 'Named arguments are not supported')) {
        // rewrite the call positionally or register a callable for the Twig callable
        throw new RuntimeException('Use positional args for this callable: '.$e->getMessage(), 0, $e);
    }
    throw $e;
}

Prevention

Only use named arguments with callables that expose a PHP signature.
When creating node-based (callable-less) Twig functions, document that named arguments are unavailable.
Prefer registering plain PHP callables so Twig can validate named arguments.

When it happens

Trigger: Calling a Twig function/filter/test registered without a callable (custom node-based callables) while using named-argument syntax, e.g. {{ special(x=1) }}.

Common situations: Custom extensions registering callables via abstract expression factories or node visitors without getCallable(); using named-argument style on core constructs that never supported it.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of twigphp/Twig@a414c3a491 (2026-09-13). Data as JSON: /api/errors/219df053fcc02b36. Report an issue: GitHub.

Appendix: source

Thrown at src/Util/CallableArgumentsExtractor.php:69

            $extractedArguments[$normalizedName = $this->normalizeName($name)] = $node;
            $extractedArgumentNameMap[$normalizedName] = $name;
        }

        if (!$named && !$this->twigCallable->isVariadic()) {
            $min = $this->twigCallable->getMinimalNumberOfRequiredArguments();
            if (\count($extractedArguments) < $this->rc->getReflector()->getNumberOfRequiredParameters() - $min) {
                $argName = $this->toSnakeCase($this->rc->getReflector()->getParameters()[$min + \count($extractedArguments)]->getName());

                throw new SyntaxError(\sprintf('Value for argument "%s" is required for %s "%s".', $argName, $this->twigCallable->getType(), $this->twigCallable->getName()), $this->node->getTemplateLine(), $this->node->getSourceContext());
            }

            return $extractedArguments;
        }

        if (!$callable = $this->twigCallable->getCallable()) {
            if ($named) {
                throw new SyntaxError(\sprintf('Named arguments are not supported for %s "%s".', $this->twigCallable->getType(), $this->twigCallable->getName()));
            }

            throw new SyntaxError(\sprintf('Arbitrary positional arguments are not supported for %s "%s".', $this->twigCallable->getType(), $this->twigCallable->getName()));
        }

        [$callableParameters, $isPhpVariadic] = $this->getCallableParameters();
        $arguments = [];
        $callableParameterNames = [];
        $missingArguments = [];
        $optionalArguments = [];
        $pos = 0;
        foreach ($callableParameters as $callableParameter) {
            $callableParameterName = $callableParameter->name;
            if (\PHP_VERSION_ID >= 80000 && 'range' === $callable) {
                if ('start' === $callableParameterName) {
                    $callableParameterName = 'low';
                } elseif ('end' === $callableParameterName) {
                    $callableParameterName = 'high';

View on GitHub (pinned to a414c3a491)