Laravel: How to log errors in form request input

I am using Laravel's form request to validate some complex input. If there is an error, Laravel returns the user to the previous page (which is fine), but I also want it to log the errors for me. How do I do that?

I attempted to use the form's withValidator method as follows, but got an error re 'maximum nesting level reached'.

public function withValidator($validator)
{
    $validator->after(function ($validator) {
        if ($validator->fails()) {
            foreach($validator->errors()->all() as $error) {
                logger($error);
            }
        }
    });
}

Calling $validator->fails() in the after callback will end in an endless loop as it calls $validator->after() in the process. It re-evaluates and does not use a previous result.

Use $validator->errors() instead and check if it is empty.