How to do Ext JS app build production and still keep the line numbers?

I tried to edit .sencha\app\production.properties with:

Code:

build.options.logger=no
build.options.debug=false
build.css.compress=true

And also .sencha/.sencha/app/app.defaults.json from:

Code:

    "production": {
    "compressor": {
            "type": "yui"
        }
    }

to

Code:

    "production": {
    "compressor": {
            "type": "none"
        }
    }

But my build\production\MyApp\app.js is still not human usable:

extjs compressed.PNG

In case it's important I make a case for this, well, in Java I keep my line numbers in my compiled code, in .Net and C++ I put symbols in productions so I get line numbers in stacks. Be able to support production issues is kind of important... so I need to know which line of my JavaScript throw a an error due a to a null reference.

How to do Ext JS app build production and still keep the line numbers?