在向Laravel添加可排队的通知时使用Laravel发送通知时发生的问题。环顾了供应商类，但看不到这样做的原因，我什至看不到任何对PDO的引用？如果有人可以帮忙

堆栈跟踪：

(1/1) PDOException
You cannot serialize or unserialize PDO instances

in Queue.php line 139
at PDO->__sleep()
at serialize(object(SendQueuedNotifications))
in Queue.php line 139
at Queue->createObjectPayload(object(SendQueuedNotifications),'queues:users')
in Queue.php line 110
at Queue->createPayloadArray(object(SendQueuedNotifications),'queues:users','')
in RedisQueue.php line 153
at RedisQueue->createPayloadArray(object(SendQueuedNotifications),'')
in Queue.php line 88
at Queue->createPayload(object(SendQueuedNotifications),'')
in RedisQueue.php line 91
at RedisQueue->push(object(SendQueuedNotifications))
in Dispatcher.php line 184
at Dispatcher->pushCommandToQueue(object(RedisQueue),object(SendQueuedNotifications))
in Dispatcher.php line 160
at Dispatcher->dispatchToQueue(object(SendQueuedNotifications))
in Dispatcher.php line 73
at Dispatcher->dispatch(object(SendQueuedNotifications))
in NotificationSender.php line 195
at NotificationSender->queueNotification(array(object(BelongsTo)),object(ThreadStartedWithProfileNotification))
in NotificationSender.php line 74
at NotificationSender->send(array(object(BelongsTo)),object(ThreadStartedWithProfileNotification))
in ChannelManager.php line 39
at ChannelManager->send(object(BelongsTo),object(ThreadStartedWithProfileNotification))
in Facade.php line 237
at Facade::__callStatic('send',array(object(BelongsTo),object(ThreadStartedWithProfileNotification)))
in UserNotification.php line 27
at UserNotification::send(object(BelongsTo),object(ThreadStartedWithProfileNotification))
in CreateController.php line 51
at CreateController->__invoke(object(Request),object(Profile))
at call_user_func_array(array(object(CreateController),'__invoke'),array(object(Request),object(Profile)))
in BoundMethod.php line 32
at BoundMethod::Illuminate\Container\{closure}()
in BoundMethod.php line 90
at BoundMethod::callBoundMethod(object(Application),array(object(CreateController),object(Closure))
in BoundMethod.php line 34
at BoundMethod::call(object(Application),array('profile' => object(Profile)),null)
in Container.php line 576
at Container->call(array(object(CreateController),array('profile' => object(Profile)))
in RoutesRequests.php line 376
at Application->callControllerCallable(array(object(CreateController),array('profile' => object(Profile)))
in RoutesRequests.php line 342
at Application->callLumenController(object(CreateController),'__invoke',array(1,array('uses' => 'App\\Http\\Controllers\\Profile\\Messaging\\CreateController','middleware' => array('unsupported','unacceptable','auth:api')),array('profile' => object(Profile))))
in RoutesRequests.php line 316
at Application->callControlleraction(array(1,array('profile' => object(Profile))))
in RoutesRequests.php line 278
at Application->callactionOnArrayBasedRoute(array(1,array('profile' => object(Profile))))
in RoutesRequests.php line 258
at Application->Laravel\Lumen\Concerns\{closure}(object(Request))
at call_user_func(object(Closure),object(Request))
in Pipeline.php line 52
at Pipeline->Laravel\Lumen\Routing\{closure}(object(Request))
in Authenticate.php line 43
at Authenticate->handle(object(Request),object(Closure),'api')
in Pipeline.php line 163
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure),object(Request))
in Pipeline.php line 32


UserNotification::send($profile->user(),new ThreadStartedWithProfileNotification(
    $profile,$thread,$accountSending
));

UserNotification：

<?php

declare(strict_types=1);

namespace Shared\Helpers;

use App\Models\User;
use RuntimeException;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Notification;
use Shared\Helpers\Contract\UserNotificationInterface;

/**
 * Class UserNotification
 * @package Shared\Helpers
 */
class UserNotification
{
    /**
     * @param $recipients
     * @param UserNotificationInterface $notification
     * @return void
     */
    public static function send($recipients,UserNotificationInterface $notification) : void
    {
        self::validate($recipients);
        Notification::send($recipients,$notification);
    }

    /**
     * @param $recipients
     * @param UserNotificationInterface $notification
     * @return void
     */
    public static function sendNow($recipients,UserNotificationInterface $notification) : void
    {
        self::validate($recipients);
        Notification::sendNow($recipients,$notification);
    }

    /**
     * @param Collection|User $recipients
     * @return void
     */
    private static function validate($recipients) : void
    {
        if ($recipients instanceof User) {
            return;
        }

        $recipients->each(function ($recipient) {
            if (! $recipient instanceof User) {
                throw new RuntimeException(sprintf(
                    'Recipient must be an instance of App\Models\User,%s given',$recipient
                ));
            }
        });
    }
}

实际通知：

<?php

declare(strict_types = 1);

namespace App\Notifications\Individual;

use App\Models\account;
use App\Models\Profile;
use App\Models\Thread;
use Illuminate\Bus\Queueable;
use Illuminate\Notifications\Notification;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Notifications\Messages\MailMessage;
use Shared\Helpers\Contract\UserNotificationInterface;
use Shared\Helpers\Helper;

/**
 * Class ThreadStartedWithProfile  Notification
 * @package App\Notifications\Individual
 */
class ThreadStartedWithProfileNotification extends Notification implements ShouldQueue,UserNotificationInterface
{
    use Queueable;

    /** @var Profile $application */
    protected $profile;

    /** @var Thread $thread */
    protected $thread;

    /** @var account $account */
    private $account;

    /**
     * ThreadStartedWithProfileNotification constructor.
     * @param Profile $profile
     * @param Thread $thread
     * @param account $account
     */
    public function __construct(Profile $profile,Thread $thread,account $account)
    {
        $this->profile = $profile;
        $this->thread = $thread;
        $this->account = $account;
    }

    /**
     * Get the notification's delivery channels.
     *
     * @param  mixed  $notifiable
     * @return array
     */
    public function via($notifiable)
    {
        return ['mail','database'];
    }

    /**
     * Get the mail representation of the notification.
     *
     * @param  mixed  $notifiable
     * @return MailMessage
     */
    public function toMail($notifiable)
    {
        return (new MailMessage)
            ->subject("{$this->account->name} Has Messaged You!")
            ->greeting("Hello")
            ->line("{$this->account->name} has messaged you on Digital Profile")
            ->action('View',Helper::url('/messaging'))
        ;
    }

    /**
     * Get the array representation of the notification.
     *
     * @param  mixed  $notifiable
     * @return array
     */
    public function toArray($notifiable)
    {
        return [
            'uuid'  => $this->thread->uuid,'account' => [
                'uuid' => $this->account->uuid,'name' => $this->account->name,'type' => $this->account->type->key,],];
    }
}