[v4] Attempting to capture STDOUT writes styles to `./true`

[vormwald]

Discussed in #15350

What version of Tailwind CSS are you using?

v4.0.0-beta.9

What build tool (or framework if it abstracts the build tool) are you using?

npx @tailwindcss/cli@next

What version of Node.js are you using?

v22.12.0

What browser are you using?

N/A

What operating system are you using?

Mac / Win

Reproduction URL

https://github.com/vormwald/tailwind-stdout-bug/

Describe your issue

I'm trying to update my jekyll plugin which captures output from Tailwind CLI and writes a new CSS file. (I'm using the executable in the tailwindcss-ruby gem. However, my repo linked above uses npx to run the CLI).

Currently, on 3.4, I omit a -o option, and the CLI writes to STDOUT.

On the v4 betas, when I omit the -o, I get the usage menu.

Unexpectedly, when I provide -o without an "output file," it writes the tailwind CSS styles to a file called "true".

[adamwathan]

Yep that seems wrong 😄 Thanks for raising, will dig in to it.

[RobinMalfait]

Hey!

This should be fixed by #15656, and will be available in the next release.