Adding backbone to dependencies causes underscore error

[grantnorwood]

When adding "bower": ['backbone'] to a js dependency, I'm getting the following error in my browser console as soon as the libs.js is loaded: "Uncaught TypeError: Cannot read property 'extend' of undefined" where _ is what is undefined.

However, I can properly use _ from the browser console, so underscore.js is indeed loaded.

Here's my manifest.json:

{
  "dependencies": {
    "main.js": {
      "files": [
        "scripts/includes/**/*.js",
        "scripts/main.js"
      ],
      "main": true
    },
    "jquery.js": {
      "bower": ["jquery"]
    },
    "libs.js": {
      "bower": [
        "modernizr",
        "foundation",
        "backbone"
      ]
    },
    "main.css": {
      "files": [
        "styles/main.scss"
      ]
    },
    "editor-style.css": {
      "files": [
        "styles/editor-style.scss"
      ]
    }
  },
  "config": {
    "devUrl": "https://dev.example.com"
  },
  "paths": {
    "source": "assets/",
    "dist": "dist/",
    "bower" : "bower_components/"
  }
}

Any idea why _ would be undefined when simply including/injecting the backbone bower dependency?

Thanks!
gkn

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[grantnorwood]

Update: The following manifest.json does load up Backbone and Underscore correctly, but only works when pointing directly to the backbone.min.js file with external: true. Additionally, even though the backbone script is referenced from the libs.js file I want to export, it is actually included in main.js.

{
  "dependencies": {
    "main.js": {
      "files": [
        "scripts/includes/**/*.js",
        "scripts/main.js"
      ],
      "main": true
    },
    "jquery.js": {
      "bower": ["jquery"]
    },
    "libs.js": {
      "files": [
        "bower_components/backbone/backbone.min.js"
      ],
      "external": true,
      "bower": [
        "modernizr",
        "foundation"
      ]
    },
    "main.css": {
      "files": [
        "styles/main.scss"
      ]
    },
    "editor-style.css": {
      "files": [
        "styles/editor-style.scss"
      ]
    }
  },
  "config": {
    "devUrl": "https://example.com"
  },
  "paths": {
    "source": "assets/",
    "dist": "dist/",
    "bower" : "bower_components/"
  }
}