# File lib/sass/less.rb, line 15
      def build_with_sass(env)
        selectors.build(env, :mixin).each do |path|
          el = path.inject(env.root) do |current, node|
            current.descend(node.selector, node) or raise MixinNameError, "#{selectors.text_value} in #{env}"
          end
          if el.is_a?(Node::Mixin::Def)
            # Calling a mixin with arguments, which gets compiled to a Sass mixin
            env << Node::Mixin::Call.new(el, [], env)
          else
            # Calling a mixin without arguments, which gets compiled to @extend
            sel = selector_str(path)
            base = selector_str(selector_base(path))
            if base == sel
              env << Node::SassNode.new(Sass::Tree::ExtendNode.new([sel]))
            else
              Haml::Util.haml_warn "WARNING: Sass doesn't support mixing in selector sequences.\nReplacing \"\#{sel}\" with \"@extend \#{base}\"\n"
              env << Node::SassNode.new(Sass::Tree::CommentNode.new("// #{sel};", true))
              env << Node::SassNode.new(Sass::Tree::ExtendNode.new([base]))
            end
          end
        end
      end