when npm install chii -g

[doerme]

Not Found - GET https://npm-registry.yy.com/koa-router/download/koa-router-8.0.8.tgz

npm ERR! code E404 npm ERR! 404 Not Found - GET https://npm-registry.yy.com/koa-router/download/koa-router-8.0.8.tgz npm ERR! 404 npm ERR! 404 'koa-router@https://npm-registry.yy.com/koa-router/download/koa-router-8.0.8.tgz' is not in this registry. npm ERR! 404 npm ERR! 404 Note that you can also install from a npm ERR! 404 tarball, folder, http url, or git url.