thinkphp Turn off debug, how can you let the third party class library throw information can be displayed

Because TP, the use of the throw function, but turn off debug, the error-throwing function is blocked.
If you throw a wrong, skip to the page error and not display the wrong content.
Like payments and other class libraries, I'm referencing, because the program is somewhat unusual to throw, and see the content, how to close in debug, and also see the thrown content.

throw new SDKRuntimeException("统一支付接口中，缺少必填参数openid！trade_type为JSAPI时，openid为必填参数！" . "
");class  SDKRuntimeException extends Exception {    public function errorMessage()    {        return $this->getMessage();    }}

