[Bug?]: Install location of one dependency (react-router-dom) changes depending on version of other, unrelated dependency (@types/react) (workspaces, monorepo, MRE attached)

[broofa]

Self-service

• I'd be willing to implement a fix

Describe the bug

Under certain circumstances, yarn is installing multiple, identical copies of a module in a monorepo when there is no reason to. This behavior is triggered by version descrepencies in modules that are unrelated to the module that's duplicated.

To reproduce

1. Download yarn_duplicate_react_router_dom_bug.zip and unzip it.

This zip file contains a minimal monorepo set up as follows:

• corepack enabled and configured for yarn@stable
• .yarnrc.yml with nodeLinker: node-modules
• top-level package.json with two workspaces: wat_1 and wat_2
• wat_1 workspace package.json depends on react-router-dom@5 and @types/react@18
• wat_2 workspace package.json depends on react-router-dom@5 and @types/react@16

Notice: The only difference in the workspaces is the version of @types/react they depend on

2. cd yarn_duplicate_react_router_dom_bug
3. ./test.sh # Run test script

You should see the following output:

$ ./test.sh
# (yarn installs)

Expected locations of react-router-dom:
./node_modules/react-router-dom

Actual locations of react-router-dom:
./node_modules/react-router-dom
./wat_2/node_modules/react-router-dom

As noted in the test, the expected behavior here is that yarn installs react-router-dom in one locatoin only, ./node_modules. If you look at the dependency graph for this monorepo, you'll see there is no overlap in the dependencies of react-router-dom and @types/react. I.e. There is no reason for yarn to be installing multiple versions of react-router-dom. Yet somehow the presence of @types/react (and the difference in it's version) in dependencies is causing the actual behavior where yarn also installs it in ./wat_2/node_modules.

Furthermore, If you change the @types/react dependency in wat_2/package.json to be the same as in wat_1/package.json and rerun the test, you'll see that you get the expected behavior:

$ cat wat_2/package.json
{
  "name": "wat_2",
  "version": "1.0.0",
  "dependencies": {
    "@types/react": "18",
    "react-router-dom": "5"
  }
}

$ ./test.sh
# (yarn installs)

Expected locations of react-router-dom:
./node_modules/react-router-dom

Actual locations of react-router-dom:
./node_modules/react-router-dom

Environment

System:
    OS: macOS 14.2
    CPU: (10) arm64 Apple M1 Max
  Binaries:
    Node: 20.11.1 - /private/var/folders/h3/trw0qb4n5t39jdpfqnt20qy80000gn/T/xfs-4ba928f7/node
    Yarn: 4.1.1 - /private/var/folders/h3/trw0qb4n5t39jdpfqnt20qy80000gn/T/xfs-4ba928f7/yarn
    npm: 10.2.4 - ~/.nvm/versions/node/v20.11.1/bin/npm

Additional context

Possibly related:

• [Feature] Able to forbid / block multiple instances of a package with peer dependencies #4688 4. 4.