npm i -d
npm info it worked if it ends with ok
npm info using npm@6.14.4
npm info using node@v13.14.0
npm info lifecycle my-site@0.1.0~preinstall: my-site@0.1.0
npm timing stage:loadCurrentTree Completed in 30ms
npm timing stage:loadIdealTree:cloneCurrentTree Completed in 1ms
npm timing stage:loadIdealTree:loadShrinkwrap Completed in 1693ms
npm http fetch GET 200 https://registry.npmmirror.com/vue-loader 202ms (from cache)
npm http fetch GET 200 https://registry.npmmirror.com/loader-utils 544ms (from cache)
npm http fetch GET 304 https://registry.npmmirror.com/chalk 841ms (from cache)
npm http fetch GET 200 https://registry.npmmirror.com/ansi-styles 53ms (from cache)
npm http fetch GET 304 https://registry.npmmirror.com/supports-color 103ms (from cache)
npm http fetch GET 304 https://registry.npmmirror.com/color-convert 1000ms (from cache)
npm http fetch GET 304 https://registry.npmmirror.com/color-name 99ms (from cache)
npm http fetch GET 304 https://registry.npmmirror.com/has-flag 92ms (from cache)
npm timing stage:loadIdealTree:loadAllDepsIntoIdealTree Completed in 5431ms
npm timing stage:loadIdealTree Completed in 8039ms
npm timing stage:generateActionsToTake Completed in 1666ms
npm timing audit submit Completed in 12554ms
npm http fetch POST 301 https://registry.npm.taobao.org/-/npm/v1/security/audits/quick 14610ms
[          ........] / extract:is-wsl: sill tarball trying mixin-deep@1.3.2 by hash: sha1-ESC0PcNZp4Xc5ltVuC4lfM9HlWY=

PS L:\Vue3Test\MyVue3Proj1\my-site> npm i mockjs@^1.1.0
npm WARN notsup Unsupported engine for commander@9.4.0: wanted: {"node":"^12.20.0 || >=14"} (current: {"node":"13.14.0","npm":"6.14.4"})
npm WARN notsup Not compatible with your version of node/npm: commander@9.4.0

> npm run build
 
Webpack Bundle Analyzer is started at http://127.0.0.1:8888

npm i
 
> core-js@3.6.5 postinstall L:\Vue3Test\MyVue3Proj1\my-site\node_modules\core-js
> node -e "try{require('./postinstall')}catch(e){}"