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npm run start 에러 질문입니다.

21.05.13 22:31 작성 조회수 111

0

> client@0.1.0 start

> react-scripts start

There might be a problem with the project dependency tree.

It is likely not a bug in Create React App, but something you need to fix locally.

The react-scripts package provided by Create React App requires a dependency:

  "webpack": "4.44.2"

Don't try to install it manually: your package manager does it automatically.

However, a different version of webpack was detected higher up in the tree:

  C:\Users\great\Documents\prj\node_modules\webpack (version: 5.37.0)

Manually installing incompatible versions is known to cause hard-to-debug issues.

If you would prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.

That will permanently disable this message but you might encounter other issues.

To fix the dependency tree, try following the steps below in the exact order:

  1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.

  2. Delete node_modules in your project folder.

  3. Remove "webpack" from dependencies and/or devDependencies in the package.json file in your project folder.

  4. Run npm install or yarn, depending on the package manager you use.

In most cases, this should be enough to fix the problem.

If this has not helped, there are a few other things you can try:

  5. If you used npm, install yarn (http://yarnpkg.com/) and repeat the above steps with it instead.

     This may help because npm has known issues with package hoisting which may get resolved in future versions.

  6. Check if C:\Users\great\Documents\prj\node_modules\webpack is outside your project directory.

     For example, you might have accidentally installed something in your home folder.

  7. Try running npm ls webpack in your project folder.

     This will tell you which other package (apart from the expected react-scripts) installed webpack.

If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.

That would permanently disable this preflight check in case you want to proceed anyway.

P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!

위와 같은 에러가 현재 발생하고 있습니다.

제 client package.json 입니다.

{
  "name": "client",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.12.0",
    "@testing-library/react": "^11.2.6",
    "@testing-library/user-event": "^12.8.3",
    "react": "^17.0.2",
    "react-dom": "^17.0.2",
    "react-scripts": "4.0.3",
    "web-vitals": "^1.1.2"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

앞에 질문에도 package.json을 비교해보며 버전을 바꿔보라고 하셨는데 이미 eject가 되어있는 상태라 어떤 것을 바꿔야 할지 모르겠습니다.

답변 1

답변을 작성해보세요.

0

혹시 노드버전이 15인가요?

전에도 노드 15버전으로 강의듣던분들에게 dependency 이슈가 많이 발생했습니다. 

NodeJS는 짝수버전(LTS, Long Term Support Version)이 안정화버전으로 대부분의 라이브러리가 짝수버전에 맞춰 업그레이드 되니

혹시 버전이 15이시면 노드버전을 바꿔보시기 바랍니다.

SSuho님의 프로필

SSuho

질문자

2021.05.15

node 버전은 14.16.1 이고요 현재는 babel 설치 없이 진행하고 있습니다.

이상하게 서버에 babel을 설치하고 나면 오류가 생깁니다....

설치하지않고 진행해도 수업에 큰 지장은 없나요? 

네 바벨이 없이 진행해도 상관없습니다.