Roots with Sass 6.5.1

Now I examine roots/roots-sass, especially gruntfile.js. I can’t discover that it’s handling with SASS.
Lines 16 to 24:

recess: {
      dist: {
        options: {
          compile: true,
          compress: true
        },
        files: {
          'assets/css/main.min.css': [
            'assets/less/app.less'

and lines 60 to 64:

watch: {
  less: {
    files: [
      'assets/less/*.less',
      'assets/less/bootstrap/*.less'

Sorry but I guess that seems to be LESS and not SASS support!

Try the latest version?
https://github.com/roots/roots-sass/blob/master/Gruntfile.js