ionic2 问题

cli cordova更新

npm update -g cordova ionic

更新后出现错误

Error: Cannot find module '@ionic/cli-utils/bootstrap'
    at Function.Module._resolveFilename (module.js:469:15)
    at Function.Module._load (module.js:417:25)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (C:\Users\gu\AppData\Roaming\npm\node_modules\ionic\bin\ionic:15:17)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)

cnpm install -g ionic@latest（通过淘宝镜像重新安装ionic）

ionic serve

出现

? Looks like a fresh checkout! No ./node_modules directory found. Would you like to install project dependencies? (Y/n)