08 one of your dependencies babel preset react app
터미널 창에 아래와 같은 메시지가 뜰때
1One of your dependencies, babel-preset-react-app, is importing the2"@babel/plugin-proposal-private-property-in-object" package without3declaring it in its dependencies. This is currently working because4"@babel/plugin-proposal-private-property-in-object" is already in y5node_modules folder for unrelated reasons, but it may break at any6babel-preset-react-app is part of the create-react-app project, whi7is not maintianed anymore. It is thus unlikely that this bug will8ever be fixed. Add "@babel/plugin-proposal-private-property-in-obje9your devDependencies to work around this error. This will make this10go away.
원인
babel-preset-react-app이 @babel/plugin-proposal-private-property-in-object 패키지를 사용하고 있지만, 이를 자신의 의존성에서 선언하지 않았다는 경고
해결
@babel/plugin-proposal-private-property-in-object를 개발 의존성에 추가
1npm install --save-dev @babel/plugin-proposal-private-property-in-object