`corepack use` in monorepo targets root not project package.json

从 corepack use 命令的实现开始，在嵌套项目目录中使用 issue 里的命令重现该行为。跟踪它如何查找 package.json 文件，以及如何选择用于写入和安装的文件。完成的标准是：嵌套项目的 package.json 被创建或更新，同时不修改仓库根目录的 package.json，并通过重现确认结果。

Current behavior

In a monorepo if corepack use is executed in a project directory, which is a sub-directory of a monorepo root directory containing an existing package.json, it does not create or update the package.json in the project directory. Instead it makes changes to the package.json in the root of the monorepo.

The monorepo is not a workspace. Each project is separate.

Expected behavior

If corepack use is executed in a monorepo project directory, it should operate on or create a package.json in that directory not in the root directory of the monorepo.

The corepack README does not discuss how corepack use is supposed to behave in a hierarchy of directories containing their own package.json files. It says simply:

When run, this command will retrieve the latest release matching the provided descriptor, assign it to the project's package.json file, and automatically perform an install.

The Node.js documentation for corepack Configuring a package says:

The Corepack proxies will find the closest package.json file in your current directory hierarchy to extract its "packageManager" property.

I would understand this to mean that if there is a package.json in the current working directory, then corepack use should act on this package.json, and not search up the hierarchy to change a higher level package.json

Step to reproduce

Ubuntu 24.04.1 LTS, Node.js 22.13.0 LTS, Corepack 0.30.0

rm -rf ~/.cache/node/corepack
corepack enable yarn

git clone https://github.com/cypress-io/github-action
cd github-action
git clean -xfd # if repeating
cd examples/yarn-classic
corepack use yarn@1.22.22
git status

package.json in the root of the repo has been modified (not examples/yarn-classic/package.json) with the addition of

"packageManager": "yarn@1.22.22+sha512.a6b2f7906b721bba3d67d4aff083df04dad64c399707841b7acf00f6b133b7ac24255f2652fa22ae3534329dc6180534e98d17432037ff6fd140556e2bb3137e"

yarn install has been run in examples/yarn-classic, creating a new examples/yarn-classic/node_modules directory there.

Logs

The debug logs do not show which directory is being used to write a package.json file, nor which directory yarn install is being run in:

$ corepack use yarn@1.22.22
Installing yarn@1.22.22 in the project...
  corepack Installing yarn@1.22.22 from https://registry.yarnpkg.com/yarn/-/yarn-1.22.22.tgz +0ms
  corepack Downloading to /home/mike/.cache/node/corepack/v1/corepack-5003-f7268cee.b6ed3 +1ms
  corepack LastKnownGood file would be located at /home/mike/.cache/node/corepack/lastKnownGood.json +802ms
  corepack No LastKnownGood version found in Corepack home. +0ms
  corepack Download and install of yarn@1.22.22 is finished +0ms
  corepack Checking /home/mike/github/cypress-io/github-action/examples/yarn-classic/package.json +1ms
  corepack Checking /home/mike/github/cypress-io/github-action/examples/package.json +0ms
  corepack Checking /home/mike/github/cypress-io/github-action/package.json +0ms
  corepack Checking /home/mike/github/cypress-io/package.json +1ms
  corepack Checking /home/mike/github/package.json +0ms
  corepack Checking /home/mike/package.json +0ms
  corepack Checking /home/package.json +0ms
  corepack Checking /package.json +0ms

yarn install v1.22.22
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
[4/4] Building fresh packages...