[v4] `@container` is an invalid utility name

[ziloen]

What version of Tailwind CSS are you using?

v4.0.0-alpha.30

Reproduction URL

Describe your issue

I am trying to upgrade to v4, but encountered the following error when using @tailwindcss/container-queries:

`matchUtilities({ '@container' : … })` defines an invalid utility name. Utilities should be alphanumeric and start with a lowercase letter, eg. `scrollbar`

tailwindcss/packages/tailwindcss/src/compat/plugin-api.ts

Line 78 in 10a8f1a

const IS_VALID_UTILITY_NAME = /^[a-z][a-zA-Z0-9/%._-]*$/

[philipp-spiess]

@ziloen Thanks! Agree this should not break: #14793, especially also for other plugins that might do something similar. However, container queries are backed into Tailwind core since 3.2 so you might not need that plugin anymore 🙂 https://tailwindcss.com/blog/tailwindcss-v3-2#container-queries