[BUG] Dev dependency should not throw “unsupported platform” error when using --production flag on npm install

Current Behavior:

If you have a module that is not supported on your platform set in the devDependencies object in your package file and you do a production install using the --production flag, the installation fails with an “Unsupported platform” (EBADPLATFORM) error. Since the module should not be installed/used during a production install, it should also not throw an error or otherwise affect the outcome of the installation.

Expected Behavior:

A module that’s declared in devDependencies should not affect the outcome of a production install.

Steps To Reproduce:

1. Create a module, M, that specifies an OS different to the one you’re currently on in its npm package file. e.g., if you’re on a Mac, specify:

  "os": [
    "win32"
  ]

2. Create an app, A, that includes module M in its devDependencies. e.g.,

  "devDependencies": {
    "M": "1.0.0"
}

3. Do a production install on app A:

npm install --production

Note that the installation fails because module M is not supported on your system, even though you’re doing a production build and module M should not be installed or used.

Environment:

• OS (noticed/reproduced on): macOS Big Sur
• Node: 14.16.0
• npm: 7.6.3

Start by reproducing the issue with the package setup described and npm install --production on an unsupported dev dependency. Trace npm's production dependency resolution and platform validation; done means the dev dependency no longer affects the production install outcome and the reproduction completes successfully.