Why do minified versions of libs break after being bundled?

Dear Mendix,

I run into trouble when using minified libs in some widgets. The reason is that the bundled wdigets.js in wrapping the minified lib code.

'Heatmap/lib/d3-min':function(){
    // wrapped by build app
    define(["dojo","dijit","dojox"], function(dojo,dijit,dojox){
        // Minified version of d3 js. Ouch.... This fails!!!
    });
},

Versus normaly non minified lib

'Heatmap/lib/d3':function(){
    // not wrapped.. d3 full version. Happy working code!
},

Why is it wrapped, is this correct or a bug?

Cheers, Andries