Breadcrumb is not rendering with the right context

AFAICT this can only be caused by template_preprocess_breadcrumb__as_js_component(), which is something @effulgentsia wrote, so assigning to him — hoping it's a simple fix! 🤞

(That was introduced in #3505993.)

I'm running this into a situation where I don't even have the override enabled. Debugged this for couple minutes and I can confirm this isn't caused by template_preprocess_breadcrumb__as_js_component(); the problem is lower level than that. It seems likely that this is caused by the fact that we are not using the regular routes for rendering the preview, but \Drupal\Core\Breadcrumb\BreadcrumbManager::build uses the route match as the basis of rendering the breadcrumb.

That sounds plausible. That means it ties into another set of issues. Will update issue links later today.

Also: that pretty much means that the breadcrumbs block has an undeclared required context (writing on phone, can’t check right now).

XB does not yet support implicit inputs (“contexts” for block plugins).

As said, will update this issue.

Per #3516432-35: Update all XB routes to respect content entity update/field edit access of edited XB field → , that issue was forced to add an preview-only work-around → . See that comment for details.

I'm 98% confident that that work-around explains/solves exactly what @lauriii described in #4.