This is odd. It works fine for me.
I just did a fresh Sage 9 install (
composer create-project roots/sage your-theme-name dev-master), selected Tachyons as the CSS framework, and then ran
tachyons-sass) show up in
node_modules. Then, taking a look at
main.scss, it imports
For reference, here is
/** Import everything from autoload */
* Import npm dependencies
* Prefix your imports with `~` to grab from node_modules/
* @see https://github.com/webpack-contrib/sass-loader#imports
// @import "~some-node-module";
/** Import theme styles */
// `sage preset` installed this file automatically.
// Running `sage preset` again could result in automatic deletion of this file.
// Because of this, we do not recommend editing this file.
yarn build works fine as well; I can see Tachyons inside the built css.
Maybe try reinstalling Sage? I don’t know if this would have any bearing on the results, but what version of Composer, Node.js, and Yarn are you using?