Authentication Middleware & custom responses

Hi Guys,

I am referring to my previous question, that is not actually solved but marked solved by mistaken. https://laracasts.com/discuss/channels/lumen/authentication-middleware

Since Lumen has Authenticate middleware and implements check on handle method.

    public function handle($request, Closure $next, $guard = null)
    {
        if ($this->auth->guard($guard)->guest()) {
            return response('Unauthorized.', 401);
        }

        return $next($request);
    }

That's mean every routes lies under auth middleware, if unauthenticated will get same response message "Unauthorized", where as I want to return more details depending on which route triggered this error.

Routes:

// Routes requires auth
$router->group(['middleware' => 'auth'], function () use ($router) {
    $router->get('auth/logout', 'User\AuthController@logout');
    $router->get('auth/verify', 'User\AuthController@verify');
    $router->get('user/profile', 'User\UserController@profile');
});

$router->post('auth/login', 'User\AuthController@login');

What could be the possible solution?