New version of MetatagEntityFieldItemList::computeValue() is causing neverending loop and error 503

Did you run the database updates and rebuild the caches after upgrading to v2?

In my case, ensureComputedValue() was being called while computeValue() was still computing the value via a call to $renderer->executeInRenderContext. The attached patch adds a flag to prevent computing if already in the process of computing.

Thank you for the patch.

Might someone be able to turn that into a merge request so we can see how the tests work?

Also, anyone have any ideas on how to trigger this bug?

Merge request for 2.1.x created: https://git.drupalcode.org/project/metatag/-/merge_requests/180

As for how to reproduce, I'm not really sure. I do have drupal/computed_field 3.0.0 installed and the bug did seem to be on nodes that have a computed field, but tracing through the call stack I couldn't see why that would matter. It could totally be a red herring that just jumped out at me because both modules are "computing" a value.