[v4] Problems upgrading in NX Monorepo with Angular to Tailwind 4.0

[eliotis]

After following instructions for the Angular upgrade to Tailwind 4.0 I get a bunch of this:

[ERROR] Cannot apply unknown utility class: bg-white [plugin angular-sass]

    node_modules/tailwindcss/dist/lib.js:17:296:
      17 │ ...r,{onInvalidCandidate:x=>{throw new Error(`Cannot apply unknown...
         ╵                                    ^

    at onInvalidCandidate (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:17:297)
    at ee (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:12:116086)
    at /home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:17:260
    at D (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:3:3502)
    at D (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:3:3742)
    at Ce (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:17:150)
    at jr (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:33:800)
    at async Ur (/home/takis/Code/eliotis/node_modules/tailwindcss/dist/lib.js:33:1053)
    at async nt (/home/takis/Code/eliotis/node_modules/@tailwindcss/node/dist/index.js:10:3251)
    at async p (/home/takis/Code/eliotis/node_modules/@tailwindcss/postcss/dist/index.js:8:3200)

  This error came from the "onLoad" callback registered here:

    node_modules/@angular-devkit/build-angular/node_modules/@angular/build/src/tools/esbuild/stylesheets/stylesheet-plugin-factory.js:125:22:
      125 │                 build.onLoad({ filter: language.fileFilter, names...

for many utility classes that previously worked fine. I created the .postcssrc.json file as instructed (not building without it) What am I missing?

[wongjn]

Perhaps you need to use the @reference directive?

[eliotis]

Yes @wongjn, I finally realized I had to do add @reference to every single stylesheet including all my connected libs. I thought I could do it with @source in the main css file but couldn't get it to work. Maybe I'll find a better way some day.

[EinfachHans]

Is "some day" already? 😃