Error in multi main

ERROR in multi main
Module not found: Error: Cannot resolve 'file' or 'directory' /Users/xiaozhaoxia/todolist./src/index.js in /Users/xiaozhaoxia/todolist
 @ multi main

webpack.config.js 文件如下

{
var webpack = require('webpack');

module.exports ={
    entry:[
        "webpack-dev-server/client?http://127.0.0.1:8080",
        "webpack/hot/only-dev-server",
        __dirname+ "./src/index.js"
],

    output:{
        path:__dirname,
        filename: "/build/bundle.js"
},
    module: {
        loaders:[
        { test: /\.js?$/, exclude:/node_modules/,loader:'babel'},
        {test:/\.css$/, loader:"style!css"}    
        ]
},
    plugins:[
    new webpack.HotModuleReplacementPlugin()
],
devtool:'source-map'
};

}