Failed to install npm package on Docusaurus 2.0.0-beta.3

[HazyFish]

Get the following error when running command npm i docusaurus-lunr-search --save

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! Found: [email protected]
npm ERR! node_modules/react
npm ERR!   react@"^17.0.1" from the root project
npm ERR!   peer react@"^16.8.4 || ^17.0.0" from @docusaurus/[email protected]
npm ERR!   node_modules/@docusaurus/core
npm ERR!     @docusaurus/core@"2.0.0-beta.3" from the root project
npm ERR!     peer @docusaurus/core@"^2.0.0-alpha.60 || ^2.0.0" from [email protected]
npm ERR!     node_modules/docusaurus-lunr-search
npm ERR!       docusaurus-lunr-search@"2.1.14" from the root project
npm ERR!   1 more (react-dom)
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer react@"^16.8.4" from [email protected]
npm ERR! node_modules/docusaurus-lunr-search
npm ERR!   docusaurus-lunr-search@"2.1.14" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.

Here is my package.json:

{
  "name": "developer-docs",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "docusaurus": "docusaurus",
    "start": "docusaurus start",
    "build": "docusaurus build",
    "swizzle": "docusaurus swizzle",
    "deploy": "docusaurus deploy",
    "clear": "docusaurus clear",
    "serve": "docusaurus serve",
    "write-translations": "docusaurus write-translations",
    "write-heading-ids": "docusaurus write-heading-ids"
  },
  "dependencies": {
    "@docusaurus/core": "2.0.0-beta.3",
    "@docusaurus/preset-classic": "2.0.0-beta.3",
    "@mdx-js/react": "^1.6.21",
    "@svgr/webpack": "^5.5.0",
    "clsx": "^1.1.1",
    "file-loader": "^6.2.0",
    "prism-react-renderer": "^1.2.1",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "url-loader": "^4.1.1"
  },
  "browserslist": {
    "production": [
      ">0.5%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "devDependencies": {
    "@docusaurus/module-type-aliases": "^2.0.0-beta.3",
    "@tsconfig/docusaurus": "^1.0.2",
    "@types/react": "^17.0.14",
    "@types/react-helmet": "^6.1.2",
    "@types/react-router-dom": "^5.1.8",
    "typescript": "^4.3.5"
  }
}

[danielvlla]

Mine is working with the following package.json configuration. I'm on the latest beta version (2.0.0-beta.4)

{
  "name": "dev-docs",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "docusaurus": "docusaurus",
    "start": "docusaurus start",
    "build": "docusaurus build",
    "swizzle": "docusaurus swizzle",
    "deploy": "docusaurus deploy",
    "clear": "docusaurus clear",
    "serve": "docusaurus serve",
    "write-translations": "docusaurus write-translations",
    "write-heading-ids": "docusaurus write-heading-ids"
  },
  "dependencies": {
    "@docusaurus/core": "2.0.0-beta.4",
    "@docusaurus/preset-classic": "2.0.0-beta.4",
    "@mdx-js/react": "^1.6.21",
    "@svgr/webpack": "^5.5.0",
    "clsx": "^1.1.1",
    "docusaurus-lunr-search": "^2.1.14",
    "file-loader": "^6.2.0",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "url-loader": "^4.1.1"
  },
  "browserslist": {
    "production": [
      ">0.5%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

[beolson]

@HazyFish - You are probably using NPM 7. NPM 7 has a little bit different behavior when it comes to child peer dependencies - NPM 6 would warn you if you did not have a matching version of a peer dependency installed. NPM 7 will try and install peer dependencies.

The easiest fix is to force NPM to act like NPM 6.

You can do that by adding a single line to your .npmrc file -

legacy-peer-deps=true

[HazyFish]

@HazyFish - You are probably using NPM 7. NPM 7 has a little bit different behavior when it comes to child peer dependencies - NPM 6 would warn you if you did not have a matching version of a peer dependency installed. NPM 7 will try and install peer dependencies.

The easiest fix is to force NPM to act like NPM 6.

You can do that by adding a single line to your .npmrc file -

legacy-peer-deps=true

Thanks for the workaround! I think I can keep this issue open to track the dependency update progress.