[v4] Sources are not being taken into consideration with Next.js 15

[AssisrMatheus]

Tailwind: 4.0.0
Next.js: 15.1.6
MacOS: Sequoia 15.2
Node: v22.13.1
pnpm: 9.15.3
Arc Browser: 1.79.0

Reproduction URL

https://github.com/AssisrMatheus/tailwindv4-next15-no-output-repro

Setup process:

1. pnpx create-next-app@latest
2. pnpx @tailwindcss/upgrade@next
3. pnpm run dev

Describe your issue

In a brand new next.js 15 project. Tailwind v4 is only building base css and theme variables, all classes used within source files are ignored.

I have tried to turn off turbopack with no success. Rolling back node to v20 also doesn't help. Tried using postcss.config.json file format instead of current one also with no success.

Current behaviour:

Expected behaviour:

[wongjn]

Seems to be working fine for me:

Perhaps try deleting the .next folder and restarting the dev server?

[AssisrMatheus]

Enregistrement.d.ecran.le.2025-01-26.a.10.39.44.mov

Have also tried that before, unfortunately doesn't fix it

[MathieuUrstein]

Hello wongjn I'm in the exact same situation as AssisrMatheus. Tailwind is there in the css output but does not pick up any classes found in tsx files.

What do your environment look like?

Mine is the following:

@tailwindcss/postcss: 4.0.0
next: 15.1.6
postcss: 8.5.1
react: 19.0.0
tailwindcss: 4.0.0
typescript: 5.7.3
node: 22.13.0
npm: 10.9.2
macOS: 14.6.1

PS: tried removing .next folder. I even tried creating a completely new project by following the nextjs installation guide from scratch

[wongjn]

Consider checking if you have any .gitignore files higher up the file tree.

[MathieuUrstein]

Indeed it was the issue for me.
I have a .gitignore in my home directory where I publish my zsh config and some other script which makes my home ignore file look like this:

*  <--- this is the issue
!.gitignore
!.zshrc
...

Then I have some projects inside my home directory. Is there a way to configure tailwind or postcss to limit the upper scope? I tried @import "tailwindcss" source("../"); or even

@import "tailwindcss" source(none);
@source "../";

with no success.

I could also move my projects outside my home directory, but I think this scenario might happen to other people

[wongjn]

I haven't seen a way to configure tailwind or postcss to limit the upper scope unfortunately. The scanning is done in Rust, using WalkBuilder from the ignore crate:

tailwindcss/crates/oxide/src/scanner/allowed_paths.rs

Lines 35 to 38 in 7e20c3b

	pub fn resolve_paths(root: &Path) -> impl Iterator<Item = DirEntry> {
	WalkBuilder::new(root)
	.hidden(false)
	.require_git(false)

tailwindcss/crates/oxide/src/scanner/allowed_paths.rs

Lines 43 to 46 in 7e20c3b

	pub fn read_dir(root: &Path, depth: Option<usize>) -> impl Iterator<Item = DirEntry> {
	WalkBuilder::new(root)
	.hidden(false)
	.require_git(false)

[goodpixels]

I have the same issue as @MathieuUrstein . Unfortunately your answer @wongjn doesn't really help at all.

[wongjn]

I'd hoped my response would at least give some context. I'm sorry it didn't live up to your expectations.

This issue should have been fixed by #15941. Are you still experiencing explicit problems with files not being read due to a .gitignore higher up the file tree?