src/Kernel/Application.php
public function start($env)
    {
        switch ($env) {
            case 'dev':
                ini_set('display_errors', 1);
                error_reporting(1);
                $this->initWhoops();
                break;
            case 'test':
            case 'prod':
                ini_set('display_errors', 0);
                error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT & ~E_USER_NOTICE & ~E_USER_DEPRECATED);
                break;
            default:
                header('HTTP/1.1 503 Service Unavailable.', true, 503);
                die('The application environment is not set correctly.');
        }

        if (file_exists(storage_path('app.down'))) {
            throw new ExceptionHandler('The system is under maintenance.', 'We will be back very soon.');
        }

        if (! $this->hasBeenBootstrapped()) {
            $this->bootstrap();
        }

        require $this->path('routes.php');
        $this->app['route']->run();
    }
public function start($env)
    {
        switch ($env) {
            case 'dev':
                ini_set('display_errors', 1);
                error_reporting(1);
                $this->initWhoops();
                break;
            case 'test':
            case 'prod':
                ini_set('display_errors', 0);
                error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT & ~E_USER_NOTICE & ~E_USER_DEPRECATED);
                break;
            default:
                header('HTTP/1.1 503 Service Unavailable.', true, 503);
                die('The application environment is not set correctly.');
        }

        if (file_exists(storage_path('app.down'))) {
            throw new ExceptionHandler('The system is under maintenance.', 'We will be back very soon.');
        }

        if (! $this->hasBeenBootstrapped()) {
            $this->bootstrap();
        }

        require $this->path('routes.php');
        $this->app['route']->run();
    }
Kernel start

@param string $env

@return void