Error: TypeError: Cannot call method 'charAt' of undefined

[oddjobsman]

Installed npm

npm install -g r.js

r.js versions

r.js: 2.1.9, RequireJS: 2.1.9, UglifyJS2: 2.4.0, UglifyJS: 1.3.4

grunt-cli v0.1.11
grunt v0.4.2
node.js v0.10.21
Mac OSX 10.9

My Directory structure:

.
|____package.json
|____build.js
|____public
| |____app.js
|____temp
| |____edit
| |____js
| | |____app
| | | |____app.js
| | |____main.js
| | |____vendor
| | | |____backbone-min.js
| | | |____backbone.js
| | | |____dust-core-0.3.0.js
| | | |____dust-core-0.3.0.min.js
| | | |____dust-helpers-1.1.1.js
| | | |____jquery-migrate.js
| | | |____jquery-migrate.min.js
| | | |____jquery.js
| | | |____jquery.min.js
| | | |____underscore-min.js
| | | |____underscore.js

My build.js:

({
  baseUrl: "temp/js",
  mainConfigFile: "temp/js/main.js",
  modules: ["app"],
  dir: "public/js"
})

Contents of temp/js/main.js:

(function () {
  'use strict';

  requirejs.config({
    baseUrl: 'js',
    paths: {
      'jquery': 'vendor/jquery.min',
      'underscore': 'vendor/underscore-min',
      'backbone': 'vendor/backbone-min',
      'dustjs': 'vendor/dust-core-0.3.0',
      'dustHelpers': 'vendor/dust-helpers-1.1.1'
    },
    shim: {
      underscore: {
        exports: '_'
      },
      backbone: {
        deps: ['jquery', 'underscore'],
        exports: 'Backbone'
      },
      dustjs: {
        exports: 'dust'
      },
      dustHelpers: {
        deps: ['dustjs']
      }
    }
  });

})();

I see this error when I run r.js:

$ r.js -o build.js
Error: TypeError: Cannot call method 'charAt' of undefined
    at Object.exports.normalize (path.js:336:27)

Not sure what is wrong. Is it due to an issue in the way I have setup my project. If so, please help me with suggestions to fix it.

Thanks.

[jrburke]

In the build.js, looks like the modules property is not correctly specified. I expect this to work better:

modules: [{
  name: "app"
}],

[fbiville]

Would you think it'd be possible to add an explicit check on this with a more explicit error message?

[listenrightmeow]

Can we please get a more explicit check on this issue? When the key is not defined as 'name' in the modules array object, the error is extremely mis-leading.