Error: Serialization of 'CurlHandle' is not allowed in serialize()

I had hoped that DependencySerializationTrait would take care of reinitialising the logger, but I see that the object indeed appears in the serialized text, which I found out using the following code:

$feed = \Drupal\feeds\Entity\Feed::load(3);
$state = $feed->getState('fetch');
$state_serialized = serialize($state);
var_dump($state_serialized);

To fix this, \Drupal\feeds\State should implement __sleep() to prevent the $logger property from being serialized and implement __wakeup() to restore the logger again.

It would be cool if we could add a Unit or Kernel test that fails when the logger would get serialized. Probably it would work to mock \Psr\Log\LoggerInterface and let its __sleep() method throw a \LogicException, similar as how \Drupal\Core\Site\Settings does this for example.

Note: since DependencySerializationTrait already implements __sleep() and __wakeup(), these methods should be aliased and then be called from the State::__sleep() and State::__wakeup() respectively.

I think that the code provided in the MR should fix the issue for you.

@kevin w
Do you want to test it?

I guess not serializing the logger creates some problems...

The fix was relatively simple, \Drupal\Core\DependencyInjection\DependencySerializationTrait::__sleep() must be compatible with Drupal\feeds\State::__sleep(). So I removed the return value for it.

Because there is now an issue related to this one opened whose fix would cause overlap with this one, I merged the code. Feel free to reopen this issue if it didn't completely fix the problem for you.

The related issue: #3487439: Error: Call to undefined method Drupal\feeds\State::messenger()