[Bug?]: tailwind setup error: [postcss] root.markClean is not a function

[dkhunt27]

What's not working?

after setting up a new redwoodjs project and then setup tailwind, get the following error when running

➜  yarn rw dev                 
web |   ➜  Local:   http://localhost:8910/
web |   ➜  Network: http://192.168.0.103:8910/
web | [postcss] root.markClean is not a function
web | 4:04:49 PM [vite] Internal server error: [postcss] root.markClean is not a function
web |   Plugin: vite:css
web |   File: /home/redwood-20240831-tailwind/web/src/index.css

How do we reproduce the bug?

$ yarn create redwood-app --ts ./redwood-tailwind
$ cd redwood-tailwind
$ yarn install
$ yarn rw dev (everything is working)
$ yarn rw setup ui tailwindcss
$ yarn rw dev (getting error)

What's your environment? (If it applies)

System:
    OS: macOS 14.6.1
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.16.0 - /private/var/folders/0z/yn7jhkyn0d738ffq_xmpwm0w0000gn/T/xfs-cdb953b8/node
    Yarn: 4.3.0 - /private/var/folders/0z/yn7jhkyn0d738ffq_xmpwm0w0000gn/T/xfs-cdb953b8/yarn
  Databases:
    SQLite: 3.43.2 - /usr/bin/sqlite3
  Browsers:
    Chrome: 128.0.6613.113
    Safari: 17.6
  npmPackages:
    @redwoodjs/core: 7.7.4 => 7.7.4 
    @redwoodjs/project-config: 7.7.4 => 7.7.4 
  redwood.toml:
    [web]
      title = "Redwood App"
      port = 8910
      apiUrl = "/.redwood/functions" # You can customize graphql and dbauth urls individually too: see https://redwoodjs.com/docs/app-configuration-redwood-toml#api-paths
      includeEnvironmentVariables = [
        # Add any ENV vars that should be available to the web side to this array
        # See https://redwoodjs.com/docs/environment-variables#web
      ]
    [api]
      port = 8911
    [browser]
      open = true
    [notifications]
      versionUpdates = ["latest"]

Are you interested in working on this?

• I'm interested in working on this

[Tobbe]

Thanks for the issue report @dkhunt27
This is an issue with postcss, see postcss/postcss#1966

We've updated to a newer version of PostCSS, but no stable Redwood release has been yet that includes the updated version.
For now you can upgrade to Redwood's canary release (yarn rw upgrade -t canary), set TW up manually, or wait for our next stable release (hopefully just a few days from now)

[ahaywood]

I just tried recreating this issue and it looks like this has been fixed in one of the latest releases.