npm 安装出错 npm ERR! request to https://registry.npmjs.org/express failed, reason: unable to verify th

npm 安装 jointjs时 出现

D:\Project\demo>npm install jointjs
npm ERR! code UNABLE_TO_VERIFY_LEAF_SIGNATURE
npm ERR! errno UNABLE_TO_VERIFY_LEAF_SIGNATURE
npm ERR! request to https://registry.npmjs.org/jointjs failed, reason: unable to
verify the first certificate

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Administrator\AppData\Roaming\npm-cache\_logs\2018-03-23T1
3_48_24_524Z-debug.log

设置下npm config set strict-ssl false 就行了，一个大坑。