Apache Error 500 instead of Laravel error ( whoops something went wrong )

PHP 7.0.5 Apache 2.4.18 Ubuntu 16.04 LTS Laravel 5.2

Apache returns error 500 instead of laravel error ( whoops something went wrong ) when I simply put in router something like this ( should return notice about undefined $b )

Route::get('/', function () {
    $a = $b;
});

777 chmod on strorage and bootstrap folders is already setted.

How to recieve laravels errors and get their description in logs?

via Chebli Mohamed