ShippingOrderProcessor not registered well? I'm trying to implement @jsacksick solution which should force displaying shipping costs on cart page (normally it doesn't exist at that step yet). I created a new module for this and it's structure is simple:
shipping_fix
  src
    ShippingOrderProcessor.php
  shipping_fix.info.yml
  shipping_fix.module
  shipping_fix.services.yml

ShippingOrderProcessor.php is exact copy of @jsacksick class:
https://gist.github.com/jsacksick/fde031197df92236ef5a916775e17a2e
info file contains:
name: Shipping fix
description: Fixes missing shipping info on cart page
type: module
core: 8.x
dependencies:

module file is empty and services file contains:
services:
  shipping_fix.shipping_order_processor:
    class: Drupal\shipping_fix\ShippingOrderProcessor
    tags:
      - { name: commerce_shipping.shipping_order_processor, priority: -300 }

But it's not working. I tried setting break points inside __construct() and process() methods of that class, but they are never reached.
Tried changing last row here to:
 - { name: commerce_order.order_processor, priority: -300 }

as explained here: https://docs.drupalcommerce.org/commerce2/developer-guide/orders/order-refresh-and-process
but then my site crashes when I try to clear the cache?
So to me it looks like that I didn't register this processor object well. Most likely problem is in services file, but I can't figure out what it is (&quot;commerce_shipping.shipping_order_processor&quot; is correct value?).
Tried dumping services with drush like:
drush devel:services
drush devel-container-services
drush devel-services

and even devel mode is turned on for each try I get:
Command &quot;devel-container-services&quot; is not defined.
or similar.
I activated the my module of course, tried clearing caches, but didn't help.
Update:
The error which I get when I change last row of services file to:
 - { name: commerce_order.order_processor, priority: -300 }

is:
Service 'shipping_fix.shipping_order_processor' for consumer 'commerce_order.order_refresh' does not implement Drupal\commerce_order\OrderProcessorInterface.
And ShippingOrderProcess.php file starts with:
&lt;?php declare(strict_types=1);

namespace Drupal\my_module\OrderProcessor;

use Drupal\commerce_order\Entity\OrderInterface;
use Drupal\commerce_order\OrderProcessorInterface;
use Drupal\commerce_shipping\ShipmentManagerInterface;
use Drupal\commerce_shipping\ShippingOrderManagerInterface;
use Drupal\profile\Entity\Profile;

/**
 * Ensures there are shipments from the start.
 */
final class ShippingProcessor implements OrderProcessorInterface {

  /**
   * The shipping order manager.
   *
   * @var \Drupal\commerce_shipping\ShippingOrderManagerInterface
   */
  protected $shippingOrderManager;

  /**
   * The shipment manager.
   *
   * @var \Drupal\commerce_shipping\ShipmentManagerInterface
   */
  protected $shipmentManager;


  public function __construct(ShippingOrderManagerInterface $shippingOrderManager, ShipmentManagerInterface $shipmentManager) {
    $this-&gt;shippingOrderManager = $shippingOrderManager;
    $this-&gt;shipmentManager = $shipmentManager;
  }

...

Update 2:
Managed to clear the cache:
For my file structure name space has to be:
namespace Drupal\shipping_fix;

Also changed servies file and now it looks like:
services:
  shipping_fix.shipping_order_processor:
    class: Drupal\shipping_fix\ShippingProcessor
    arguments: ['@commerce_shipping.order_manager', '@commerce_shipping.shipment_manager']
    tags:
      - { name: commerce_order.order_processor, priority: -300 }

Now cache clearing works, but I still don't see shipping costs on cart page...
In this case, you'll want to run this before the commerce_shipping.early_order_processor, set priority to 300
services:
  shipping_fix.shipping_order_processor:
    class: Drupal\shipping_fix\ShippingProcessor
    arguments: ['@commerce_shipping.order_manager', '@commerce_shipping.shipment_manager']
    tags:
      - { name: commerce_order.order_processor, priority: 300 }