Error: Missing either an "out" or "dir" config value.

Below is my build configuration file: build.js

({
    appDir: '../src',
    baseUrl: 'libs',
    paths: {
        app: 'js'
    },
    dir: '../prod',
    out:"../js/main-built.js",
    fileExclusionRegExp: /.less$/,
    optimize: "uglify2",
    optimizeCss: "standard",
    modules: [{
        name: '../js/main'
    }]
})

I am using "grunt-requirejs": "~0.4.2" as my build npm and Gruntfile requirejs configuration + r.js 2.1.16:

requirejs: {
    std: {
        options: grunt.file.read('config/build.js')
    }
}

Whenever i am try to execute grunt requirejs it is throwing below error on my console:

Error: Error: Missing either an "out" or "dir" config value. If using "appDir" for a full project optimization, use "dir". If you want to optimize to one file, use "out".
    at Function.build.createConfig (d:\app\node_modules\grunt-requirejs\node_modules\requirejs\bin\r.js:27717:19)

I want to consolidate some of the JS files like jquery and its plugins etc. into 1 file and i am using AMD pattern similar to project https://github.com/hegdeashwin/Protocore

Can you please help me out here and tell what i have missed in my configuration ?

Thanks & RegardsError: Missing either an "out" or "dir" config value.

asciidisco / grunt-requirejs

Error: Missing either an "out" or "dir" config value. #105