[BUG] workspaces `install-strategy = "nested"` does not install/ignores dependencies

Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

npm does not install dependencies of package-b when install-strategy = "nested", and package-b is nested in another package (package-a). Not in the root of the workspace or the package itself.

- package-a
  - package-b
    package.json (dependencies of b)
  package.json (dependencies of a)
- package.json (workspaces)

Expected Behavior

Install the dependencies of package-b.

Steps To Reproduce

1. clone https://github.com/samuelstroschein/reproduction-npm-nested-packages-bug
2. run npm i

Environment

• npm: v8/v9/v10 happens on every version of npm
• Node.js: v18/v20
• OS Name: Mac OS
• System Model Name:
• npm config:

; "user" config from /Users/samuel/.npmrc

access = "public" 
legacy-peer-deps = false 

; "project" config from /Users/samuel/Desktop/repro/.npmrc

install-strategy = "nested" 

; node bin location = /Users/samuel/.nvm/versions/node/v20.8.0/bin/node
; node version = v20.8.0
; npm local prefix = /Users/samuel/Desktop/repro
; npm version = 10.1.0
; cwd = /Users/samuel/Desktop/repro
; HOME = /Users/samuel
; Run `npm config ls -l` to show all defaults.

Clone the linked reproduction repository and run npm i with install-strategy = "nested" enabled in .npmrc; inspect the workspace layout involving package-a and nested package-b. Confirm the missing dependencies and trace npm's workspace installation behavior. Done means package-b's dependencies are installed when package-b is nested under package-a.