mkdir -p my-app
mkdir -p my-lib

echo '{
  "packageManager": "pnpm@10.13.1"
}' > package.json

echo 'packages:
  - '\''my-app'\''
  - '\''my-lib'\''' > pnpm-workspace.yaml

echo 'link-workspace-packages=true' > .npmrc

echo '{
  "name": "my-app",
  "dependencies": {
    "@super-secret/my-lib": "2.0.0"
  }
}' > my-app/package.json

echo '{
  "name": "@super-secret/my-lib",
  "version": "1.0.0",
}' > my-lib/package.json

 ERR_PNPM_FETCH_404  GET https://registry.npmjs.org/@super-secret%2Fmy-lib: Not Found - 404

This error happened while installing a direct dependency of 

@super-secret/my-lib is not in the npm registry, or you have no permission to fetch it.

No authorization header was set for the request.

Legend: production dependency, optional only, dev only

my-app@1.0.0

dependencies:
@super-secret/my-lib link:../my-lib