Showing error in yarn start command says This package doesn't seem to be present in your lockfile; try to make an install to update your resolutions

Question

The error shown when yarn start command is given

Error details:

Internal Error: confusion@workspace:.: This package doesn't seem to be present in your lockfile; try to make an install to update your resolutions
    at J.getCandidates (C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:2:276872)
    at i.getCandidates (C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:2:266282)
    at C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:2:286432    at C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:57:349928
    at new Promise (<anonymous>)
    at e.exports (C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:57:349910)
    at o (C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:57:349611)
    at C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:57:349684
    at C:\Users\risha\Desktop\Front-End Web Development with React\.yarn\releases\yarn-berry.js:57:349727
    at new Promise (<anonymous>)

My package.json file is

{
  "name": "confusion",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-scripts": "3.4.1"
  }

}

I have tried adding

"scripts":{
  "start":"react-scripts start"
}

But no change in the error.

Answer 1

Cross-posting from this question:

The problem in here seems to be an existing yarn.lock file inside of one of the workspaces. Deleting it solves the problem.

More info:

Example: 3 workspaces: 2 create-react-app (app, home) and one shared component: (components)

Inside the component folder a lingering yarn.lock file exists. Remove it.

Also check that:

1. All your workspaces have "private:true" in each of their package.json (same level as name, private, source).
2. Check that you have added your workspaces inside a "workspaces" key in the main package.json
3. When you're executing yarn workspaces myworkspace myworkspace matches the name of your workspace in its package.json. In my case, the name of the workspace inside the components folder is called @schon/components, so I need to address it as yarn worksapces @schon/components instead.

Answer 2

It means a certain package is not installed, and you need to install it.

• Try running yarn install to install the required packages.
• If this does not work, try deleting the node_modules folder and run yarn install again.
• If it fails, delete both node_modules folder and yarn.lock file and run yarn install.