* yarn install 하기
npm i yarn
* 오류
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.
* 디버깅
npm-cache를 삭제했으나 오류가 안고쳐졌다
* 해결
npm install --global yarn
global로 옵션 바꿔서 설치했더니 전체에서 잘 작동한다.
특정 dir에만 적용되도록 설치됬었던 것 같다.