mochajs/mocha — pull request #1406 by lukebayes (2014-10-29 21:30:38+00:00)
Title: This reporter outputs "undefined" when run in nodejs.

Found the root cause with the following code:

var oldLog = console.log;
console.log = function(msg) {
oldLog.apply(console, arguments);
if (msg === undefined) {
throw new Error('FOUND IT!');
}
};

Which provided this output:

Error: FOUND IT!
at Console.console.log ([project]/test/test_helper.js:16:11)
at Runner. ([project]/node_modules/mocha/lib/reporters/dot.js:54:13)
at Runner.EventEmitter.emit (events.js:117:20)
at [project]/node_modules/mocha/lib/runner.js:596:10
at [project]/node_modules/mocha/lib/runner.js:517:7
at next ([project]/node_modules/mocha/lib/runner.js:246:23)
at Object._onImmediate ([project]/node_modules/mocha/lib/runner.js:275:5)
at processImmediate [as _immediateCallback] (timers.js:336:15)