webpack 配置 postcss

{  test: /\.scss/,  
loader: 'style-loader!css-loader!postcss-loader!sass-loader?outputStyle=expanded'},

module.exports = {  
srcPath: srcPath,  
publicPath: '/assets/',  
port: dfltPort,  
getDefaultModules: getDefaultModules,  
postcss: function () {   
 return [      
      require('autoprefixer')({        
        browsers: ['last 2 versions', 'ie >= 8']      
       })    
    ];  
  }
};

webpack 配置 postcss 如果遇到下面的问题：

ERROR in ENOENT: no such file or directory, scandir '/Users/chengzehe/Desktop/github/own-project/startReact/node_modules/node-sass/vendor'
 @ ./src/styles/App.scss 4:14-186 13:2-17:4 14:20-192
webpack: bundle is now VALID.

请直接 npm rebuild node-sass