인프런 커뮤니티 질문&답변

강의대로 따라하다가, 

npm run dev를 치고 엔터를 치는데,

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:

  "babel-jest": "^24.9.0"

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

However, a different version of babel-jest was detected higher up in the tree:

  /home/sj/node_modules/babel-jest (version: 25.3.0) 

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 "babel-jest" 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 /home/sj/node_modules/babel-jest is outside your project directory.

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

  7. Try running npm ls babel-jest in your project folder.

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

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!

와 같은 에러가 뜨더라구요. 터미널에서 하라고 한대로 했는데, skip preflight check를 true 로 하면은 실행은 됩니다. 근데 이거는 일시적인 해결방법이라고 하더라구요.

skip preflight check=true로 하면 실행은 되는데, 터미널에는 이런 메세지가출력됩니다

[1] ./src/components/views/LandingPage/LandingPage.js

[1]   Line 2:10:  'FaCode' is defined but never used  no-unused-vars

[1] 

[1] ./src/components/views/LoginPage/LoginPage.js

[1]   Line 74:11:  'dirty' is assigned a value but never used        no-unused-vars

[1]   Line 79:11:  'handleReset' is assigned a value but never used  no-unused-vars

[1] 

[1] ./src/components/views/RegisterPage/RegisterPage.js

[1]   Line 92:11:  'dirty' is assigned a value but never used        no-unused-vars

[1]   Line 97:11:  'handleReset' is assigned a value but never used  no-unused-vars

[1] 

[1] Search for the keywords to learn more about each warning.

[1] To ignore, add // eslint-disable-next-line to the line before.

[1] 

[1] [HPM] Error occurred while trying to proxy request /api/users/auth from localhost:3000 to http://localhost:5000 (ECONNREFUSED) (https://nodejs.org/api/errors.html#errors_common_system_errors)

맨 아래의 2줄은 제외하곤 eslint 떄문에 일어나는 오류인 거 같은데, 맨 아래 2줄의 메세지가 어떤 뜻인지 잘 모르겠습니다. 도움 주시면 감사하겠습니다