Twig reset function returns blank screen

Little explanation

() PHP: . : twig var_dump , VarDumper.

, , VarDumper , twig dump(), symfony VarDumper, , .

, VarDumper dump() native var_dump() ( VarDumper ). VarDumper dump() - , / .

• VarDumper,
• : vendor/twig/twig/lib/Twig/Extension/Debug.php
• twig_var_dump
• var_dump() dump()
• / ob_start() + ob_get_clean() ( var_dump(), , dump() )

+ , ;)

function twig_var_dump(Twig_Environment $env, $context)
{
    if (!$env->isDebug()) {
        return;
    }

//    ob_start();

    $count = func_num_args();
    if (2 === $count) {
        $vars = array();
        foreach ($context as $key => $value) {
            if (!$value instanceof Twig_Template) {
                $vars[$key] = $value;
            }
        }

        dump($vars);
    } else {
        for ($i = 2; $i < $count; $i++) {
            dump(func_get_arg($i));
        }
    }

//    return ob_get_clean();
}

PS: 2013 , , , .

:

"symfony/symfony": "2.5.*"
"symfony/var-dumper": "~2.6"