Circular reference detected for service "hook_event_dispatcher.module_handler"

We got the same issue from today.
Getting it after drush cr command.
If I do drush cim then 1 time it's clean and I can run any command.
After that, I'm getting again this error.

The only solution at the moment is to uninstall webprofiler and tracer.

mikkmiggur are you using the hook_event_dispacther module as bob.hinrichs ?

There's a hotfix patch that would circumvent the error: https://www.drupal.org/project/hook_event_dispatcher/issues/3385203#comm... 🐛 Circular reference detected for service "hook_event_dispatcher.module_handler" Active

After applying the patch above I was still seeing this error.
In my case I was using drupal/office_hours → which seems to call the ModuleHandler very very early in their .module file.

I fixed it by replacing those two lines with:

require_once __DIR__ . '/office_hours.theme.inc';
require_once __DIR__ . '/office_hours.theme.exceptions.inc';

Leaving it here in case it might help someone else.

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

This problem has resurfaced for us:

hook_event_dispatcher: 4.2.0
tracer: 1.0.4
drupal core: 10.4.5
We are running lando with a pantheon recipe (if that matters).

When hook_event_dispatcher and tracer are enabled, and one runs drush updb, the following error results:

Circular reference detected for service "hook_event_dispatcher.module_handler", path: "hook_event_dispatcher.module_handler -> hook_event_dispatcher.manager -> hook_event_dispatcher.module_handler".

Some guesses as to why this is:

This error occurs during updb, because it has a special bootstrap mode that ensures all modules are loaded and update hooks are discovered in a single run, so it is instantiating the whole thing at once, and bringing the circular reference to light. Whereas in a normal page request, some services are only loaded on demand.

Tracer’s services include:

plugin.manager.tracer:
class: Drupal\tracer\TracerPluginManager
parent: default_plugin_manager

TracerPluginManager extends Drupal’s DefaultPluginManager. That core base class automatically loads the module_handler. If you then have a circular dependency from module_handler → hook_event_dispatcher.manager → module_handler, enabling Tracer is the catalyst that triggers it during drush updb. \Drupal\tracer\TracerPluginManager extends DefaultPluginManager and calls parent::__construct. This parent class requires module_handler.

I will add an issue for tracer and cross-reference this, since I don't have enough understanding to know where the fix would reside, if a fix is possible.

Curious to see if this is reproducible by others.