内容如下

npm WARN deprecated @hapi/joi@15.1.1: Switch to 'npm install joi'
npm WARN deprecated request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
npm WARN deprecated @hapi/address@2.1.4: Moved to 'npm install @sideway/address'
npm WARN deprecated @hapi/bourne@1.3.2: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/topo@3.1.6: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/hoek@8.5.1: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated har-validator@5.1.5: this library is no longer supported
npm WARN deprecated uuid@3.4.0: Please upgrade  to version 7 or higher.  Older versions may use Math.random() in certain circumstances, which is known to be problematic.  See https://v8.dev/blog/math-random for details.
npm WARN deprecated graphql-tools@4.0.8: This package has been deprecated and now it only exports makeExecutableSchema.\nAnd it will no longer receive updates.\nWe recommend you to migrate to scoped packages such as @graphql-tools/schema, @graphql-tools/utils and etc.\nCheck out https://www.graphql-tools.com to learn what package you should use instead
npm WARN deprecated graphql-extensions@0.15.0: The  API has been removed from Apollo Server 3. Use the plugin API instead: https://www.apollographql.com/docs/apollo-server/integrations/plugins/
npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
npm WARN ws@7.5.3 requires a peer of bufferutil@^4.0.1 but none is installed. You must install peer dependencies yourself.
npm WARN ws@7.5.3 requires a peer of utf-8-validate@^5.0.2 but none is installed. You must install peer dependencies yourself.

npm ERR! code EEXIST
npm ERR! syscall symlink
npm ERR! path ../lib/node_modules/@vue/cli/bin/vue.js
npm ERR! dest /usr/local/bin/vue
npm ERR! errno -17
npm ERR! EEXIST: file already exists, symlink '../lib/node_modules/@vue/cli/bin/vue.js' -> '/usr/local/bin/vue'
npm ERR! File exists: /usr/local/bin/vue
npm ERR! Remove the existing file and try again, or run npm
npm ERR! with --force to overwrite files recklessly.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/air/.npm/_logs/2021-08-06T07_58_32_001Z-debug.log

解决方法
open /usr/local/bin 删除bin文件夹中 vue文件后重新安装

结果

➜  ~ npm install -g @vue/cli
npm WARN deprecated @hapi/joi@15.1.1: Switch to 'npm install joi'
npm WARN deprecated request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142
npm WARN deprecated @hapi/address@2.1.4: Moved to 'npm install @sideway/address'
npm WARN deprecated @hapi/bourne@1.3.2: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/topo@3.1.6: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated @hapi/hoek@8.5.1: This version has been deprecated and is no longer supported or maintained
npm WARN deprecated har-validator@5.1.5: this library is no longer supported
npm WARN deprecated uuid@3.4.0: Please upgrade  to version 7 or higher.  Older versions may use Math.random() in certain circumstances, which is known to be problematic.  See https://v8.dev/blog/math-random for details.
npm WARN deprecated graphql-tools@4.0.8: This package has been deprecated and now it only exports makeExecutableSchema.\nAnd it will no longer receive updates.\nWe recommend you to migrate to scoped packages such as @graphql-tools/schema, @graphql-tools/utils and etc.\nCheck out https://www.graphql-tools.com to learn what package you should use instead
npm WARN deprecated graphql-extensions@0.15.0: The  API has been removed from Apollo Server 3. Use the plugin API instead: https://www.apollographql.com/docs/apollo-server/integrations/plugins/
npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
/usr/local/bin/vue -> /usr/local/lib/node_modules/@vue/cli/bin/vue.js

> core-js-pure@3.16.0 postinstall /usr/local/lib/node_modules/@vue/cli/node_modules/core-js-pure
> node -e "try{require('./postinstall')}catch(e){}"

Thank you for using core-js ( https://github.com/zloirock/core-js ) for polyfilling JavaScript standard library!

The project needs your help! Please consider supporting of core-js:
> https://opencollective.com/core-js 
> https://patreon.com/zloirock 
> https://paypal.me/zloirock 
> bitcoin: bc1qlea7544qtsmj2rayg0lthvza9fau63ux0fstcz 

Also, the author of core-js ( https://github.com/zloirock ) is looking for a good job -)


> @apollo/protobufjs@1.2.2 postinstall /usr/local/lib/node_modules/@vue/cli/node_modules/@apollo/protobufjs
> node scripts/postinstall


> ejs@2.7.4 postinstall /usr/local/lib/node_modules/@vue/cli/node_modules/ejs
> node ./postinstall.js

Thank you for installing EJS: built with the Jake JavaScript build tool (https://jakejs.com/)

npm WARN ws@7.5.3 requires a peer of bufferutil@^4.0.1 but none is installed. You must install peer dependencies yourself.
npm WARN ws@7.5.3 requires a peer of utf-8-validate@^5.0.2 but none is installed. You must install peer dependencies yourself.

+ @vue/cli@4.5.13
added 931 packages from 584 contributors in 51.962s
➜  ~ vue ui
🚀  Starting GUI...
🌠  Ready on http://localhost:8000