[Bug?]: Regression Yarn 3.0 creates self-reference link for each workspace

Self-service

• I’d be willing to implement a fix

Describe the bug

Yarn 3.0 creates a self-reference link for each workspace which does not happen with v2.4.2

To reproduce

const fs = require('fs')

fs.writeFileSync('.yarnrc.yml', 'nodeLinker: node-modules \r\n nmHoistingLimits: workspaces')

await packageJson({ name: 'root', workspaces: ['packages/*'] })
await packageJson({ name: 'package-a' }, { cwd: 'packages/package-a' })
await yarn('install')

expect(fs.existsSync('packages/package-a/node_modules/package-a')).toBe(false);

Environment

System: OS: macOS 11.5 CPU: (12) x64 Intel® Core™ i7-9750H CPU @ 2.60GHz Binaries: Node: 16.5.0 - /private/var/folders/p4/8995l80n0m10v308tf59n7xc0000gp/T/xfs-30c2485c/node Yarn: 3.0.0 - /private/var/folders/p4/8995l80n0m10v308tf59n7xc0000gp/T/xfs-30c2485c/yarn npm: 7.19.1 - ~/.nvm/versions/node/v16.5.0/bin/npm

Additional context

➜ yarn -v     
2.4.2

➜ tree
.
├── node_modules
├── package.json
├── packages
│   └── package-a
│       └── package.json
└── yarn.lock

3 directories, 3 files

➜ yarn set version latest
➤ YN0000: Downloading https://github.com/yarnpkg/berry/raw/master/packages/yarnpkg-cli/bin/yarn.js
➤ YN0000: Saving the new release in .yarn/releases/yarn-3.0.0.cjs
➤ YN0000: Done in 1s 460ms

➜ yarn install           
➤ YN0000: ┌ Resolution step
➤ YN0000: └ Completed
➤ YN0000: ┌ Fetch step
➤ YN0000: └ Completed
➤ YN0000: ┌ Link step
➤ YN0000: └ Completed
➤ YN0000: Done in 0s 103ms

➜ yarn -v     
3.0.0

➜ tree
.
├── node_modules
├── package.json
├── packages
│   └── package-a
│       ├── node_modules
│       │   └── package-a -> ..
│       └── package.json
└── yarn.lock

5 directories, 3 files

You can see the new symbolic link created.

I did not find this behavior as intended in the breaking changes of Yarn 3.0. I’m really sorry if I missed it.

[sparebytes]

An option to disable the self-references in yarn would help me work around an issue I’m having with babel. An ELOOP: too many symbolic links encountered error occurs when using babel even though I’ve specified --ignore "**/node_modules". The error occurs before any babel config is loaded.

[larixer]

@loremaps It is intended, I’m sorry it caused trouble for you. Not creating self-references can be seen as a bug, since it will deviate from the pnp linker results, and the linkers should behave as close as achievable. I understand that sometimes self-references are not wanted, probably having a setting to disable them globally or on per-workspace basis would be the way to go.