Symfony Translation Command Error: Call to Undefined Method PhpParser\Node\Expr\Variable::toString()

I recently upgraded my Symfony project from 5.4 to 6.4.13. Now, I am encountering an error when running the Symfony translation debug php bin/console debug:translation en command in my project. The error message is as follows:

Attempted to call an undefined method named "toString" of class "PhpParser\Node\Expr\Variable".

Project Details:

• Symfony version: 6.4.13
• PHP version: 8.1
• Composer dependencies include symfony/translation v6.4.13.
• Configuration: translation.yaml:

framework:
    default_locale: '%env(APP_LANGUAGE)%'
    translator:
        default_path: '%kernel.project_dir%/translations'
        fallbacks: '%application_locales%'

Question: how to resolve this error?

The debug:translation command parses PHP code to extract strings. In particular, it extracts strings of the form:

class::name

Here is the relevant part of the AbstractVisitor::getStringValue() method:

if ($node instanceof Node\Expr\ClassConstFetch) {
    try {
        $reflection = new \ReflectionClass($node->class->toString());
        $constant = $reflection->getReflectionConstant($node->name->toString());
        if (false !== $constant && \is_string($constant->getValue())) {
            return $constant->getValue();
        }
    } catch (\ReflectionException) {
    }
}

The code assumes that $node->class is a literal node and calls toString() on it. However, one of your files contains:

$this::NAME

In that case, $node->class is a Variable node, which has no toString() method, and the call throws an exception.

As a workaround, you can access the constant using the explicit class name:

YourClass::NAME