Hugo can't build SCSS: you need the extended version

You add a theme, run hugo server, and the build stops with something like:

error: error building site: TOCSS: failed to transform "scss/main.scss" (text/x-scss): this feature is not available in your current Hugo version

The theme is probably fine. The installed Hugo binary simply does not include SCSS support.

Why this happens

Hugo ships in two builds:

• Standard – the plain hugo binary.
• Extended – the same, plus a Sass/SCSS compiler (and WebP encoding).

Hugo Extended includes SCSS compilation. A theme using Hugo’s Sass pipeline fails on the standard binary with a TOCSS error.

Check which build you have

hugo version

The extended build says so, right in the string:

hugo v0.150.2+extended darwin/arm64

The version number can differ. If the output does not include extended, the standard build is active.

Install the extended version

Homebrew installs extended by default:

brew install hugo

Direct download: on Hugo’s releases page, pick the asset with extended in the name (hugo_extended_…_darwin-universal.tar.gz), unpack it, and put hugo on your PATH.

With Go:

CGO_ENABLED=1 go install -tags extended github.com/gohugoio/hugo@latest

After installation, run hugo version and confirm that the output contains +extended.

Still failing after you installed extended?

• Two Hugos on your PATH. You installed extended, but an older standard binary still comes first. which -a hugo lists them; hugo version tells you which one actually runs. Remove the standard one, or fix the order.
• CI or GitHub Actions. It builds locally and fails in the cloud because the runner installed standard Hugo. In peaceiris/actions-hugo (or your setup step), set extended: true.

In HugoKit: automatic installation uses Hugo Extended. Existing Hugo installations are used as found.