[v4] Windows error: MultiByteToWideChar when using --watch

[mookman288]

Tailwind Version: v4.1.7
Tailwind CLI Version: v4.1.7
Operating System: Windows 10, Pro, x64
Node Version: v18.20.7 (+ newer)

I'm using the following script:

"dev:css": "npx @tailwindcss/cli -i ./src/css/stylesheet.css -o ./css/stylesheet.css --watch"

Here's the full output when using tailwindcss:

≈ tailwindcss v4.1.7

node:internal/process/promises:288
            triggerUncaughtException(err, true /* fromPromise */);
            ^
[Error: MultiByteToWideChar: The operation completed successfully.]

This appears to work fine if I remove --watch flag. Takes about 2s to generate a sheet, which is a little slow, but not surprising.

I tested this with node versions 20.19.2, 21.7.3, and 22.16.0.

I also tried switching from powershell (with UTF-8 support via command line process) to cmd.exe, and also tried ConEmu.

Hopefully someone else has encountered this and has a suggestion. I couldn't find anything via Google about this specific use case with Tailwind.

I'll switch back to 3.x for now, but would like to try out v4 at some point in the future.

Thanks for reading!