Declaration of Drupal\Core\DependencyInjection\DependencySerializationTrait::__wakeup() must be compatible

I'll leave that issue open for others to find it. But the the fix is wrong!

The correct fix is to not include the DependencySerializationTrait anymore as this one is already included by PluginBase.
This way the implementation in Search API works and we already committed that change to Search API Solr.

https://git.drupalcode.org/project/search_api_solr/-/commit/8fffe9c2be66...

Hi Markus,
could you please create a new release then?

I think I would be faster if people stop asking over different channels and if I need to answer less questions ;-)

I tried commenting put DependencySerializationTrait as per #4 but then I still receive

Fatal error: Declaration of Drupal\search_api_solr\Plugin\search_api\backend\SearchApiSolrBackend::__sleep() must be compatible with Drupal\search_api\Backend\BackendPluginBase::__sleep(): array in /var/www/html/web/modules/contrib/search_api_solr/src/Plugin/search_api/backend/SearchApiSolrBackend.php on line 5077

Rolling back to from search api from 1.35 to 1.34 seems to resolve the problem for me (for now).

tried commenting put DependencySerializationTrait as per #4 but then I still receive

Fatal error: Declaration of Drupal\search_api_solr\Plugin\search_api\backend\SearchApiSolrBackend::__sleep() must be compatible with Drupal\search_api\Backend\BackendPluginBase::__sleep(): array in /var/www/html/web/modules/contrib/search_api_solr/src/Plugin/search_api/backend/SearchApiSolrBackend.php on line 5077

You mix two different issues here. Removing DependencySerializationTrait fixes __wakeup(), not __sleep()!

https://www.drupal.org/project/search_api_solr/releases/4.3.4 →

Thank you!