Runtime error causing crash

[tacman]

I'm trying to help debug twigphp/Twig#4528 (reply in thread) and thought it'd be cool to add smoke testing to it. But it's causing my machine to freeze until the process finally dies:

You can re-create it by cutting and pasting this. I think the problem is with the guard tag, but thought I'd report it here in case you can improve the testing itself.

symfony new ignore-dump-in-production --webapp && cd ignore-dump-in-production
bin/console make:controller AppController
sed -i "s|/app|/|" src/Controller/AppController.php

cat <<'EOF' > templates/app/index.html.twig
{% extends 'base.html.twig' %}
{% block body %}
    {% guard function dump  %}
       {{ dump() }}
    {% else %}
        dump cannot be used in production
    {% endguard %}
{% endblock %}
EOF

composer require --dev pierstoval/smoke-testing
cat <<'EOF' > tests/AllRoutesTest.php
<?php

namespace App\Tests;
use Pierstoval\SmokeTesting\SmokeTestStaticRoutes;

class AllRoutesTest extends SmokeTestStaticRoutes
{
    // That's all!
}
EOF

vendor/bin/phpunit

On my machine. this dies:

No security vulnerability advisories found.
Using version ^1.1 for pierstoval/smoke-testing
PHPUnit 9.6.22 by Sebastian Bergmann and contributors.

Testing 
Killed

[Pierstoval]

I just tried it and it works fine on my machine:

Maybe it's related to PHP or its config?

Can you upload the output of php --version and php -i so I can see if it's coming from my package itself?