[BUG] install-strategy=linked: npm exec -w <ws> ignores a workspace-local bin and falls back to the registry #9616

Part of #9608.

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

This is not just a request to bump a dependency for a CVE

• This is not solely a request to bump a dependency for a CVE

Current Behavior

A workspace depends on another workspace that provides a bin. The bin shim is correctly created in the consumer workspace's node_modules/.bin/, but npm exec -w <ws> -- <bin> under install-strategy=linked ignores it and falls through to the registry, producing npm error code E404 (exit 1). The hoisted strategy runs the local bin.

Expected Behavior

npm exec -w <ws> -- <bin> should run the workspace-local bin under the linked strategy, as it does under hoisted, without contacting the registry.

Steps To Reproduce

cd "$(mktemp -d)"
echo 'install-strategy=linked' > .npmrc
echo '{ "name": "root", "version": "1.0.0", "workspaces": ["packages/*"] }' > package.json
mkdir -p packages/a packages/tool
echo '{ "name": "a", "version": "1.0.0", "dependencies": { "tool": "*" } }' > packages/a/package.json
echo '{ "name": "tool", "version": "1.0.0", "bin": { "zz-bin": "cli.js" } }' > packages/tool/package.json
printf '#!/usr/bin/env node\nconsole.log("tool bin ok")\n' > packages/tool/cli.js
chmod +x packages/tool/cli.js
npm install >/dev/null
readlink packages/a/node_modules/.bin/zz-bin   # ../tool/cli.js  (bin from dep workspace, present)

npm exec -w a -- zz-bin
#   linked:  npm error code E404  GET https://registry.npmjs.org/zz-bin   (exit 1)
#   hoisted: prints "tool bin ok" (exit 0)

Environment

• npm: 12.0.0-pre.1 (latest)
• Node.js: v24.17.0
• OS Name: macOS (Darwin 25.5.0)
• System Model Name: MacBook (arm64)
• npm config:

install-strategy=linked