Ruby (with rbenv and Bundler), Sass, Compass (with config.rb), and scss-lint configuration for a Drupal 7 / 8 theme.

.ruby-version

2.3.1

.scss-lint.yml

scss_files: 'scss/**/*.scss'

linters:
  ImportantRule:
    exclude:
      - 'scss/_mixins.scss'
  NestingDepth:
    max_depth: 4
  PropertySortOrder:
    exclude:
      - 'scss/_mixins.scss'
    order: smacss
  QualifyingElement:
    allow_element_with_class: true
  SelectorDepth:
    max_depth: 5

config.rb

#
# @file
# Compass Compass CSS Authoring Framework configuration.
#
require 'compass/import-once/activate'

http_path       = "/themes/custom/EXAMPLE/"
css_dir         = "css"
sass_dir        = "scss"
images_dir      = "images"
javascripts_dir = "js"

output_style = :expanded

relative_assets = true

line_comments = false

Gemfile

# frozen_string_literal: true
source "https://rubygems.org"

gem "sass"
gem "compass"
gem "scss_lint", require: false