今天升级了Angular-cli版本到：Angular CLI: 6.2.4 后，初始化了个新项目，cnpm install 安装好依赖后 ng serve 报错。
报错信息如下：
** Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ **
95% emitting LicenseWebpackPlugin(node:21768) UnhandledPromiseRejectionWarning: Error: ENOENT: no such file or directory, open 'D:\me\angular\ngApp\node_modules\_@[email protected]@@angular\package.json'
at Object.fs.openSync (fs.js:646:18)
at Object.fs.readFileSync (fs.js:551:33)
at LicenseExtractor.readPackageJson (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\LicenseExtractor.js:126:23)
at LicenseExtractor.parsePackage (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\LicenseExtractor.js:23:32)
at ModuleProcessor.processPackage (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\ModuleProcessor.js:44:46)
at ModuleProcessor.processFile (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\ModuleProcessor.js:41:21)
at fileCallback (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\LicenseWebpackPlugin.js:107:61)
at moduleCallback (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\LicenseWebpackPlugin.js:114:21)
at D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\LicenseWebpackPlugin.js:126:29
at Array.forEach (<anonymous>)
at emitCallback (D:\me\angular\ngApp\node_modules\[email protected]@license-webpack-plugin\dist\LicenseWebpackPlugin.js:92:32)
at _err0 (eval at create (D:\me\angular\ngApp\node_modules\[email protected]@tapable\lib\HookCodeFactory.js:32:10), <anonymous>:19:1)
at callback (D:\me\angular\ngApp\node_modules\[email protected]@copy-webpack-plugin\dist\index.js:77:17)
at D:\me\angular\ngApp\node_modules\[email protected]@copy-webpack-plugin\dist\index.js:118:24
at <anonymous>
(node:21768) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:21768) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.在各种百度、谷歌、stack overfolw后解决方法：
（1）第一种解决办法：使用yarn代替cnpm安装依赖包
然后使用yarn遇到了一连串的问题，解决方法和安装使用方法请参考我的另一篇博文：《yarn踩坑记录》
最后 ng serve 成功运行：
D:\me\angular\ng-app>ng serve
** Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ **
Date: 2018-10-10T02:12:20.302Z
Hash: 239e5b9b82b5dbe931da
Time: 10477ms
chunk {main} main.js, main.js.map (main) 10.7 kB [initial] [rendered]
chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 227 kB [initial] [rendered]
chunk {runtime} runtime.js, runtime.js.map (runtime) 6.22 kB [entry] [rendered]
chunk {styles} styles.js, styles.js.map (styles) 15.6 kB [initial] [rendered]
chunk {vendor} vendor.js, vendor.js.map (vendor) 3.28 MB [initial] [rendered]
i ｢wdm｣: Compiled successfully.（2）第二种解决方法：使用npm 代替cnpm安装依赖包
D:\me\angular\ng-app>npm install个人来说还是推荐第一种使用yarn来安装依赖包，yarn的使用方法和npm大同小异；但是第二种使用npm安装的方式，在有vpn的条件下还是不错的，不然等待你的将会是一大堆安装失败、警告的报错信息。