How to access mixins and variables in twbs:bootstrap?


I’m wondering how I can access variables and mixins in the twbs:bootstrap package, if I’m not using LESS, but rather fourseven:scss. I’ve tried the following in a SCSS file:

@import "{twbs:bootstrap}/less/mixins/buttons.less";

And this doesn’t work. It says it failed to find the file. I’ve tried buttons.scss and buttons.sass as well, more as shots in the dark. Do I just have to translate the LESS mixins into SCSS and copy them into my project manually?