Gruntjs 如何在grunt contrib less中使用较少插件的干净css？

我正在尝试使用，但无法使其运行。grunt配置似乎无法找到或安装插件。这是我用的叉子

我已经用以下内容更新了Gruntfile.js：

grunt.initConfig({
...
less: {
  compileCore: {
    options: {
      strictMath: true,
      sourceMap: true,
      outputSourceFiles: true,
   +  plugins: [
   +    (new require('less-plugin-clean-css')({
   +      "advanced": true,
   +      "compatibility": "ie8"
   +    }))
   +   ],
      sourceMapURL: '<%= pkg.name %>.css.map',
      sourceMapFilename: 'dist/css/<%= pkg.name %>.css.map'
    },
    src: 'less/bootstrap.less',
    dest: 'dist/css/<%= pkg.name %>.css'
  ...
  }
},

运行

grunt

并获取此错误：

Running "less:compileCore" (less) task
>> TypeError: Cannot read property 'install' of undefined

---

我遗漏了什么？

正确的语法需要额外的括号：

plugins: [
    (new (require('less-plugin-clean-css'))({
        advanced: true,
        compatibility: 'ie8'
    }))
]

plugins: [
    (new (require('less-plugin-clean-css'))({
        advanced: true,
        compatibility: 'ie8'
    }))
]