[Bug] `webpack` cannot access `webpack-cli` with workspaces

[HosseinAgha]

Describe the bug

webpack-cli throws an error "One CLI for webpack must be installed." in a workspace but works fine in a single package.
I think this may be a major bug with binaries and workspaces in berry.

To Reproduce

Checkout the repro repository: https://github.com/HosseinAgha/yarn2-workspaces-webpack-bug-repro

[arcanis]

It's a Webpack bug. They are using require.resolve to check whether webpack-cli is installed, but they don't run it on behalf on their parent package. This causes Yarn to reject the resolution because webpack-cli isn't a dependency of webpack.

Three solutions:

• As a short-term option, you can use yarn webpack-cli ..., which is the real name of the binary exposed by webpack-cli.

• The webpack package should declare webpack-cli (and webpack-command) as optional peer dependencies. This formal declaration will give it access to its neighbour packages.

• Or the webpack package should require webpack-cli on behalf of the userland code by using something similar to createRequire. The trick is to find on behalf of who should the call be made - my best guess would be process.env.INIT_CWD.

[andreialecu]

I've ran into the same issue but with webpack-dev-server:

Error: A package is trying to access another package without the second one being listed as a dependency of the first one

Required package: webpack-cli (via "webpack-cli/bin/config-yargs")
Required by: webpack-dev-server@virtual:1e73a2e864eda574311f3ce8fb25ed7e0b40837cf3d41b48f72db6961ea7b29e054e2ef16981aea4a4b040cdb56a1a6f9fe63ce21114147e55edb38884db917e#npm:3.10.1

Since the command being ran is already yarn webpack-dev-server, I'm not sure how to get around this and get unblocked. Any ideas?

Edit: Just found this PR: webpack/webpack-dev-server#2396 - guess I'll use that branch until it's merged.

[arcanis]

Note that you can use packageExtensions to fix the problem in your repo.

[andreialecu]

Adding this to .yarnrc.yml got past it:

packageExtensions:
  webpack-dev-server@*:
    peerDependencies:
      webpack-cli: "*"

[o-alquimista]

Is my issue a duplicate of this?

[yarnbot]

Hi! 👋

This issue looks stale, and doesn't feature the reproducible label - which implies that you didn't provide a working reproduction using Sherlock. As a result, it'll be closed in a few days unless a maintainer explicitly vouches for it or you edit your first post to include a formal reproduction (you can use the playground for that).

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