Can't install with composer (Twig_Extension error)

[bastien70]

Hello,

I'm trying to install the bundle but when executing the cache script, I've :

In JsFormValidatorTwigExtension.php line 13:

Attempted to load class "Twig_Extension" from the global namespace.
!! Did you forget a "use" statement?

[66Ton99]

I think it because of new Twig twigphp/Twig-extensions#243
You need use Twig less than 3.0

[bastien70]

However, my Twig version is 2.12.5 :

<p>The current version is {{ constant('Twig_Environment::VERSION') }}</p>

[66Ton99]

https://github.com/twigphp/Twig/blob/v2.12.5/lib/Twig/Extension.php - you need turn on compatibility for this