Treating warnings as errors because process.env.CI = true.

场景：jenkins使用npm构建vue前端test分支报错，shell手动构建正常

报错信息：

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! v3@0.1.0 build:test: `cross-env --REACT_APP_SKSXENV=test react-app-rewired build "CI=false"`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the v3@0.1.0 build:test script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/tomcat/.npm/_logs/2021-05-26T14_15_21_900Z-debug.log

而且，我们生产环境的jenkins使用npm构建vue前端product分支，虽然有warning级别的告警信息，却能正常构建完毕。
后仔细对比两个jenkin的构建记录，明显测试环境jenkins构建test分支的日志，明显多了下面的内容：

Creating an optimized production build...

Treating warnings as errors because process.env.CI = true.
Most CI servers set it automatically.

Failed to compile.

最后谷歌搜索关键字process.env.CI,尝试解决办法——npm build前设置该参数值为false：

node -v
yarn -v
npm -v
npm install
export CI=false
npm run build:test

问题解决，深入内容请自行查找！