npm doesn't install devDependencies recursively
===

There is `connect-assets` in my `package.json`'s dependencies. And its `package.json` looks like:

 

     "dependencies": {
        "connect-file-cache": "0.2.4",
        "mime": "1.2.2",
        "snockets": "1.3.6",
        "underscore": "1.1.7"
      },
      "devDependencies": {
        "async": "0.1.14",
        "coffee-script": "~1.3.1",
        "connect": "1.8.5",
        "nib": "0.2.0",
        "bootstrap-stylus": "0.2.0",
        "nodeunit": "0.5.4",
        "stylus": "0.22.2",
        "request": "2.1.1",
        "watchit": "0.0.4",
        "less": "1.3.0"
      }

But when I ran `npm install`(with or without `--dev` and `--dev-all`), it only installed `connect-assets`, no `stylus`, `nib`, etc. 

How should I do?