[Enhancement]: yarn on Windows with nodeLinker set to node-modules creates symlinks as absolute paths in node_modules folder

Self-service

• I’d be willing to implement a fix

Describe the bug

Yarn 3.2.4 Windows 10 Node 18.x Docker node-linker

Running ‘yarn install’ on multiple workspaces that use ‘portal:’ or ‘workspace:’ to reference other workspaces results in symlinks in the top level node_modules that are absolute paths.

Running ‘yarn install’ on the same monorepo creates symlinks with relative paths, as expected.

The issue is with mounting the filesystem into Docker containers for running consistent builds.

The absolute paths are broken in Docker because we mount just the project directory as a Docker volume, not an entire hard drive.

Relative paths, as created in Yarn on Linux work correctly,

E.g.

Partial listing of node_modules when yarn install is run on Linux:

common-dev-tools -> ../common/dev-tools
common-front -> ../common/front
common-front-and-back -> ../common/front-and-back

vs. exact same repo, but yarn install run from WIndows:

common-dev-tools -> C:\Users\jeff.wishnie\source\repos\xxx\common\dev-tools\     
common-front -> C:\Users\jeff.wishnie\source\repos\xxx\common\front\ 
common-front-and-back -> C:\Users\jeff.wishnie\source\repos\xx\common\front-and-back\

To reproduce

// sorry, this issue is only windows, so sherlock can’t be used. Instead here are high-level reproduction steps

• Create a new project: yarn init -2
• edit .yarnrc.yml to set nodeLiker to node-modules
• Create two workspaces: packages/a; packages/b
• Edit package json to add: workspaces: packages/*
• Add package a as a dependency in package b:
  • (from package/b): yarn add a@“workspace:*”

From WINDOWS run yarn install NOTICE: the link created in node_modules is absolute not relative

Environment

System:
    OS: Windows 10 10.0.19044
    CPU: (16) x64 11th Gen Intel(R) Core(TM) i7-11850H @ 2.50GHz
  Binaries:
    Node: 18.11.0 - 
    Yarn: 3.2.4
    npm: 8.19.2

Additional context

No response

[merceyz]

Before I make a PR, question: should it make the PR to master or to a 3.x branch?

master, I’ll backport it if needed.

Changes are exclusive to nm-linker plugin, so just bumped plugin-nm and cli . not sure if everything that depends on CLI (other plugins) needs bumping as well?

Nothing else needs to be bumped in this case 👍

[jeff-wishnie]

Bingo! https://github.com/yarnpkg/berry/blob/77e525a7e33581b38c86bfb80da075ce84f9a9f6/packages/plugin-nm/sources/NodeModulesLinker.ts#L677