Unexpected error when using @source inline() with a leading space in Tailwind v4 #19227

akhilsugunan77 · 2025-10-29T09:11:00Z

akhilsugunan77
Oct 29, 2025

Tailwind throws an error while building, When using the @source inline() function with a space as the first character inside the parentheses.

// globals.css
@source inline( '{sm:,md:,lg:,xl:,}grid-cols-{1,2,3,4,5,6,7,8,9,10,11,12}');
               ^empty space here

❯ npm run build

> vite-react-typescript-starter@0.0.0 build
> vite build

vite v5.4.8 building for production...
(node:29) ExperimentalWarning: WASI is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
✓ 3 modules transformed.
x Build failed in 114ms
error during build:
[@tailwindcss/vite:generate:build] `@source` paths must be quoted.
file: /home/project/src/index.css
    at eval (file:///home/project/node_modules/tailwindcss/dist/chunk-OQ4W6SLL.mjs:52:4460)
    at hr (file:///home/project/node_modules/tailwindcss/dist/chunk-OQ4W6SLL.mjs:23:1718)
    at I (file:///home/project/node_modules/tailwindcss/dist/chunk-OQ4W6SLL.mjs:23:1377)
    at zi (file:///home/project/node_modules/tailwindcss/dist/chunk-OQ4W6SLL.mjs:52:2752)
    at async Ba (file:///home/project/node_modules/tailwindcss/dist/chunk-OQ4W6SLL.mjs:58:631)
    at async Module.Hu (file:///home/project/node_modules/tailwindcss/dist/chunk-OQ4W6SLL.mjs:58:1406)
    at async Module.nu (file:///home/project/node_modules/@tailwindcss/node/dist/index.mjs:37:3484)
    at async D.generate (file:///home/project/node_modules/@tailwindcss/vite/dist/index.mjs:16:3920)
    at async Object.transform (file:///home/project/node_modules/@tailwindcss/vite/dist/index.mjs:16:2561)

tailwind version tested on 4.1.16

Tailwind playground: https://play.tailwindcss.com/ZI9MC8ioVg?file=css
Another repo: https://bolt.new/~/sb1-bmrctyvb

I think the expected output should either be