After upgrade build fails

[peter-pr]

What is your Hugo Extended Version

hugo v0.144.2+extended+withdeploy darwin/amd64

What is your Go Version

go1.24.0 darwin/amd64

What is your Node.js Version

node@v23.7.0

What is your Operating System

mac

Check for Existing Issues

• I have searched and found no relevant issues.

Expected Behavior

npm run dev to be successful, but its not

Steps to Reproduce

npm run dev

Start building sites …
hugo v0.144.2+extended+withdeploy darwin/amd64 BuildDate=2025-02-19T12:17:04Z VendorInfo=brew

Built in 1398 ms
Error: error building site: TAILWINDCSS: failed to transform "/css/main.css" (text/css): Error: Failed to find 'tailwindcss'
in [
mysite/website/mysite-site
at /node_modules/postcss-import/lib/resolve-id.js:35:13
/node_modules/postcss/lib/lazy-result.js:293:11)
/node_modules/tailwindcss/lib/cli/build/index.js:49:9)

Code Reproduction URL

No response

Additional Information

I ran these before npm run dev

npm run update-theme
npm run update-modules

[pasdengl]

The issue seems to have been introduced in commit 02085ff. Before that the build runs smoothly.

[tfsomrat]

Hey @pasdengl, can you share your repository? Also, it's a big update, and many dependencies have been changed. So it's recommended that you fork or clone the latest code instead of using the update-theme script.

[Anth0rx]

@tfsomrat We use Hugoplate here and run into the same problem. We use Hugoplate as a submodule in themes/hugoplate and pull in the latest changes occasionally. We do dot use the update-theme script.

Initially we used npm run project-setup to set up the example project and make custom changes in layouts folder.

[Anth0rx]

@tfsomrat I managed to update to the latest version of Hugoplate for our site with a set of manual changes.

Especially the changed keys in theme.json caused the issue:

Error: Cannot apply unknown utility class: text-text-dark

This has not been obvious, since the string text-text-dark is not declared anywhere, but instead is put together from theme.json.

[suzannealdrich]

I ran into a similar issue after updating Hugo, which caused the build for my site to fail. I had originally created my repo from the hugoplate template, so syncing in the latest theme changes was tricky. I wanted to preserve commit history and properly merge upstream changes instead of copying files over.

What worked for me

Following this Stack Overflow answer, I was able to rebase and merge the theme updates into my project.

Here’s what I did:

1. Added the original theme repo as a remote
   I named it template:

   git remote add template git@github.com:zeon-studio/hugoplate.git
   git fetch template

2. Identified commit hashes

   • ORIGINAL_COMMIT_ID: The commit from hugoplate I originally based my repo on
   • YOUR_FIRST_COMMIT: The first commit in my own repo (sjaconsulting)
     (You can get this by running: git rev-list --max-parents=0 HEAD)

3. Rebased my work onto the upstream commit
   I followed this pattern:

   git rebase --onto ORIGINAL_COMMIT_ID YOUR_FIRST_COMMIT master

4. Merged in the latest changes from hugoplate

   git merge template/master

5. Resolved conflicts by hand, especially around config and customizations.

6. Force pushed the new history (since I had rebased):

   git push --force

You can see my rebase commit here:
👉 sjaconsulting/sjaconsulting@3e60167

After this, both npm run dev and npm run build started working again 🎉