执行命令cnpm i --save-dev node-sass sass-loader出现错误，
错误如下：
D:\Users\wangyanjun\webstorm-workspace\birdhelper\vue-imooc-ebook>cnpm i --save-dev node-sass sass-loader

• [1/2] Installing nan@^2.10.0content buffer: {“type”:“Buffer”,“data”:[]}
  × Install fail! SyntaxError: Unexpected end of JSON input (file: D:\Users\wangyanjun\webstorm-workspace\birdhelper\vue-imooc-ebook\node_modules_inherits
  @2.0.3@inherits\package.json)
  SyntaxError: Unexpected end of JSON input (file: D:\Users\wangyanjun\webstorm-workspace\birdhelper\vue-imooc-ebook\node_modules_inherits@2.0.3@inherits\p
  ackage.json)
  at JSON.parse ()
  at Object.readJSON (D:\Users\Administrator\AppData\Roaming\nvm\v11.0.0\node_modules\cnpm\node_modules\npminstall\lib\utils.js:33:17)
  at readJSON.next ()
  at onFulfilled (D:\Users\Administrator\AppData\Roaming\nvm\v11.0.0\node_modules\cnpm\node_modules\co\index.js:65:19)
  npminstall version: 3.14.0
  npminstall args: D:\Users\Administrator\AppData\Roaming\nodejs\node.exe D:\Users\Administrator\AppData\Roaming\nvm\v11.0.0\node_modules\cnpm\node_modules
  npminstall\bin\install.js --fix-bug-versions --china --userconfig=C:\Users\wangyanjun.cnpmrc --disturl=https://npm.taobao.org/mirrors/node --registry=htt
  ps://registry.npm.taobao.org --save-dev node-sass sass-loader
  希望能解答下，困扰了很久了。谢谢