--link-duplicates error

[STRML]

Do you want to request a feature or report a bug?

This is a bug in the pre-release 0.21.2 version with the --link-duplicates flag.

What is the current behavior?

Installing a project with @kadira/storybook and webpack@2 results in the following error:

error An unexpected error occurred: "EEXIST: file already exists, link '/home/git/forks/yarn-link-bug/node_modules/@kadira/storybook/node_modules/enhanced-resolve/node_modules/memory-fs/.npmignore' -> '/home/git/forks/yarn-link-bug/node_modules/babel-loader/node_modules/enhanced-resolve/node_modules/memory-fs/.npmignore'".

Please mention your node.js, yarn and operating system version.

Node 6.9.2, Yarn 0.21.2, OSX Sierra.

Reproduction Repository

A reproduction is available.

Ref: #2620 (comment) and this tweet. My preference would be for the feature to remain as it gives us significant (20%) size savings on our frontend project.

[felixfbecker]

I am meeting this too, essentially I cannot use the option because it doesn't work reliably.
I need every little speed improvement in the linking phase, since it seems like we will not see a no cache option in the near future (yarnpkg/rfcs#53)

[bestander]

Can't fetch a private package IIRC An unexpected error occurred: "https://registry.yarnpkg.com/@kadira/storybook-addon-links/-/storybook-addon-links-1.0.1.tgz: Request failed "503 Service Unavailable"".

[bestander]

I wonder if the error is related to @ in file path

[felixfbecker]

@bestander would it help if I figured out another reproduction case?

[bestander]

Of course

[bestander]

Even more help would be to find out the cause of the issue, the core linking logic is implemented here https://github.com/yarnpkg/yarn/blob/master/src/util/fs.js#L513 and here

yarn/src/package-linker.js

Line 232 in 0ad2bf9

await fs.hardlinkBulk(Array.from(hardlinkQueue.values()), this.reporter, {

[michaeloscarli]

Is this issue still being tracked?

[bestander]

Afaik no one in the core team is actively working on fixing that, help from the community is expected.

[navarroaxel]

With the new webpack@3.0.0 an error appears when I use --link-duplicates. This didn't happen with webpack@2.6.1.

Steps to reproduce:

mkdir test && cd test
yarn add webpack webpack-stream webpack-dev-middleware --link-duplicates

result:

error An unexpected error occurred: "EEXIST: file already exists, link '/test/node_modules/uglifyjs-webpack-plugin/node_modules/enhanced-resolve/node_modules/memory-fs/.gitattributes' -> '/test/node_modules/webpack-dev-middleware/node_modules/enhanced-resolve/node_modules/memory-fs/.gitattributes'".

I tested it using several version combinations:
node@6.11.0 and node@8.1.2
yarn@0.24.6 and yarn@0.26.1

[bestander]

looking into it now