The newest version of Jekyll Sass Converter [uses sass-embedded](https://jekyllrb.com/news/2022/12/21/jekyll-sass-converter-3.0-released/) for stylesheets, and it seems like that just isn't available on Alpine Linux (see e.g. https://github.com/sass/dart-sass-embedded/issues/85, https://github.com/sass/dart-sass-embedded/issues/106).