Webpack Sass文件编译两次

我有以下网页包配置：

规则：

{
    test: /\.scss$/,
    use: [
        MiniCssExtractPlugin.loader,
        {
            loader: 'css-loader',
            options: {
                sourceMap: false
            }
        }, {
            loader: 'sass-loader',
            options: {
                sourceMap: false,
                processCssUrls: false
            }
        }
    ]
}

插件：

new MiniCssExtractPlugin({
    filename: '[name].css',
    chunkFilename: '[id].css'
})

当使用

SpeedMeasurePlugin

构建和查看输出时，我得到这样的输出：

mini-css-extract-plugin, and 
css-loader, and 
sass-loader took 12.73 secs
  module count = 1
css-loader, and 
sass-loader took 12.66 secs
  module count = 1

---

为什么sass要编译两次？

这是MiniCssExtractPlugin，它运行两次sass加载程序。不知道为什么