use Illuminate\Database\Eloquent\Model;

class Person extends Model
{
    public function setAttribute($key, $value)
    {
        if ($key == 'xxx') { // 'xxx' 是你想要监听的属性
            throw new \RuntimeException;
        }
        
        return parent::setAttribute($key, $value);
    }
}

use Illuminate\Database\Eloquent\Model;

class Person extends Model
{
    public function setAttribute($key, $value)
    {
        if ($key == 'xxx') { // 'xxx' 是你想要监听的属性
            try {
                throw new \RuntimeException;
            } catch (\RuntimeException $e) {
                \Log::error($e->getTraceAsString());
            }
        }

        return parent::setAttribute($key, $value);
    }
}

$a = null;

var_dump($a->c);