Hook dojo.require to insert line-number tracing calls into blocks. Call DbG() from the console to access the resulting trace object.

debug.js

// A hack to insert simple line number tracing into javascript code included with dojo.require
// Add a URL parameter trace to invoke line-by-line printing on the console or
// trace=silent to collect the messages in an array, you can retrieve them with DbG()
DbG =
(function () {
    // get the url parameters
    var parms = dojo.queryToObject(window.location.search.substring(1));
    var flag = parms.trace;
    if (typeof(flag) == 'undefined') {
        // bail if not requested
        return null;
    }
    console.log('tracing', flag);

    // setup the tracing function
    var func; // return this below
    if (flag == 'silent') {
        var trace = [];
        func = function(file, line, context) {
            if (typeof(file) == 'undefined') {
                return trace;
            }
            trace.push(file + ' ' + line + ' ' + context);
        }
    } else {
        func = function(file, line, context) {
            console.log(file, line, context);
        }
    }
    // hook the function dojo uses to fetch the code
    var _getText = dojo._getText;
    function myGetText(fname) {
        // call dojo._getText to get its output
        var txt = _getText.apply(this, arguments);

        // only match Javascript files
        var name = fname.match(/(\w+)\.js$/);
        if (name == null) {
            return txt; // bail this isn't js
        }
        name = name[1]; // get the base name
        // rewrite the text insert calls to our trace function at the beginning of code blocks
        // we work line-by-line. Of course this doesn't work with all coding styles. 
        // Don't do that.
        txt = dojo.map(txt.split('\n'), function(line, i) {
            // only work on lines ending with {, this excludes some useful cases but avoids
            // getting triggered inside strings. If you want a block traced, put a newline after {
            if(!/\{\s*$/.test(line)) return line;
            // try to pick up some useful context from the line
            var context = line.match(/[a-zA-Z_][a-zA-Z_0-9. ]+/) || '';
            return line.replace(/(\)|\Welse)(\s*\{)\s*$/g,
                                '$1$2 DbG("'+name+'",'+(i+1)+',"'+context+'");');
        }).join('\n');
        return txt;
    }
    // replace their function with mine
    dojo._getText = myGetText;
    // return my trace function
    return func;
})();

This is a first hack at hook dojo.require to edit the text to insert the filename and line number to make debugging easier. Just stuffs the strings in an array for now and provides a single function to access them.

This one is a little easier to explore. The trace is an array of objects each naming a file, and the line numbers in that file.

Stick a .js on the end of the title / filename to get some syntax highlighting.

Lots of parse errors using this latest code + a non-XD dojo build.

Yes, when I tested with a non-XD build (while I was offline at the MD) I got errors and gave up.

This new one does a better job with context, I think, and is robust to some errors caused by strings in the previous one.

I should have some test for what is getting requested.