Plugin not found exception when upgrading to 2x

This actually seems to be working fine. site_settings_update_10004() update hook sets this.

But this prevent drush updb to execute.

Could be because you got it into a broken state already prior to the updb. Maybe try adding the plugin id to config and config import to manually work around it

@scott_euser Thanks for the advice, we has downgrade to 1.x with no error ☺️

Would be better if we can get to the bottom of this though. Can you provide steps to reproduce from a clean install with 1.x then upgrading? When I try the updb hook seems to work fine.

I ran also into the same issue that drush updb did not run the update-hook as mentioned in this comment 🐛 Plugin not found exception when upgrading to 2x Needs work . As a quick remedy to fix a broken site you can re-run the update-hook via drush:
drush php-eval "\Drupal::moduleHandler()->loadInclude('site_settings', 'install'); site_settings_update_10004();"
Afterwards fllush the cache with drush cr and the site should be up and running again.

Thanks for the tip: are you able to reproduce it eg from a backup? If so perhaps could check whether it needs to be change to a post update hook instead to account for particular scenarios?

Unfortunately I can't. We run Gitlab-pipelines where the system is always doing a drush updb on every run and after installing version 2.0 it did also run updb but it missed this update_hook it seems which left the site broken. Why I it did not run the update-hook I can't really tell. The upgrade was done with composer on Drupal 10.2.2 - maybe that helps to narrow it down?

Best I can think of is the updated Merge Request here to just re-run the update hook as a post update hook. Hopefully someone can give this a spin!

Okay this doesn't hurt at least, so will merge and can always re-open or add a follow-up.

Automatically closed - issue fixed for 2 weeks with no activity.

This still doesn't work for me.

When I make changes and switch from 8.x-2.0 to 2.0.0-alpha2, I get:

drush status
Error: Class "Drupal\site_settings\SiteSettingsLoader" not found in Drupal\Component\DependencyInjection\Container->createService() (line 259 of /var/www/html/docroot/core/lib/Drupal/Component/DependencyInjection/Container.php).
 [warning] Drush command terminated abnormally.

So I run cache clear to clear that error, but then subsequently I cannot run any drush command, incl.:

drush cr

In DiscoveryTrait.php line 53:
                                                                                                                                
  The "" plugin does not exist. Valid plugin IDs for Drupal\site_settings\SiteSettingsLoaderPluginManager are: flattened, full  

Or the update hook as per #8:

drush php-eval "\Drupal::moduleHandler()->loadInclude('site_settings', 'install'); site_settings_update_10004();"

In DiscoveryTrait.php line 53:
                                                                                                                                
  The "" plugin does not exist. Valid plugin IDs for Drupal\site_settings\SiteSettingsLoaderPluginManager are: flattened, full  

Or configuration set:

drush cset site_settings.config loader_plugin 'flattened'

In DiscoveryTrait.php line 53:
                                                                                                                                
  The "" plugin does not exist. Valid plugin IDs for Drupal\site_settings\SiteSettingsLoaderPluginManager are: flattened, full  

It only works when I execute the above cmd ahead of checking out the 2.x codebase.

drush cset site_settings.config loader_plugin 'flattened'

 loader_plugin key does not exist in site_settings.config config. Do you want to create a new config key? (yes/no) [yes]:
 > yes

Can you try to 2.x-dev instead of the alpha release, few more commits haven't yet released in there.