Just put a not-found.tsx file in the root of your app dir.

well yes, I did think of that...

Could I make a pages/404.tsx? Does that catch notFound()?

That means you don't have a root layout in your app dir.

Yes that is indeed my problem

I'm using multiple route layouts

Doesn't mean you can't have a root layout

I know what you mean.

You still have a root layout, though. Right?

I have a layout inside each route group

But not one inside app/

You can still use a top-level layout.tsx file...

can I? it explicitly says to remove the top level layout.tsx to create multiple route layouts

But it implicitly also implies that you can (and probably should) have a top level layout file.

Try it 😂

But I don't want a top level layout, I want to have separate Root layouts

It cannot possibly implicitly imply that the correct way to make multiple Root layouts is to not make either of them the Root layout

By them saying:

"If you use multiple root layouts without a top-level layout.js file, your home page.js file should be defined in one of the route groups, For example: app/(marketing)/page.js."

They are (down to interpretation) implying that you can do it.

But hey, here's another idea - try it and see!!!!!

Mate, I am perfectly aware that if I put a top level root layout, it will work. However, I don't want a top level root layout, I want multiple root layouts. Can you not see how if there is a single root layout, then the children of that root layout are no longer root layouts

May I ask why you need it to be a "Root Layout", and not just have a layout at the root of your route group?

Because the properties on html are defined differently for each group

If its not possible to have a global not found without a root layout, that is understandable, however as of right now, this is not explicitly stated in the documentation, and it also seems to be quite a big fallacy to support multiple root layouts when doing so means not supporting a custom 404 page