奇点包括box-sizing和clearfix

Question

我想在我的Output Options设置中添加一些Singularitygs。 边框 2. clearfix

但是我收到了一些错误：

_base.scss

@import 'singularitygs';
$include-border-box: true;
$include-clearfix: true;

$grids: 12;
$gutters: 1/3; 

*, *:before, *:after {
  @include box-sizing('border-box');
}

#foo {
  @include clearfix;
}

...

config.rb

require 'singularitygs' ...

终端日志

sass/partials/_base.scss: Undefined mixin 'box-sizing'.)