Static rendering does not work with nextjs 15.

[islamBelabbes]

Description

Static rendering does not seem to work with Next.js 15

I have cloned the example repo, and I did run the Next.js 15 upgrade command.
npx @next/codemod@canary upgrade latest

Next.js logs show that the pages are static, but they are not.

I have tried both with and without generateStaticParams()

Verifications

• I've verified that the problem I'm experiencing isn't covered in the docs.
• I've searched for similar, existing issues on GitHub and Stack Overflow.
• I've compared my app to a working example to look for differences.

Mandatory reproduction URL

https://github.com/islamBelabbes/example-app-router-nextjs15-static

Reproduction description

Steps to reproduce:

1. Open reproduction
2. run npm npm build
3. Math.random() value on home pge changes on every request

Expected behaviour

home page should be static (Math.random() value should not change on every request.)

[amannn]

There's a PR where I've updated all examples to Next.js 15: #1089

I've just added Math.random() there to verify and static rendering definitely works for me there. Can you compare with the implementation of example-app-router there to see if you can spot a difference?

[islamBelabbes]

Great, it's working fine.
the issue in the prev example was that not-found.tsx was using the BaseLayout which is dynamic by default.

[amannn]

Ah yes, that's a really weird bug indeed! I've mentioned this in #1089 and opened vercel/next.js#71623. With rootParams on the horizon, I hope that we'll soon be able to support static rendering much more easily.