https://github.com/visionmedia/debug/blob/953162b4fa8849268d147f4bac91c737baee55bb/browser.js#L107 In IE9 (and probably earlier versions) `typeof console.log` returns `object`. Thus no logs are ever output.
https://github.com/visionmedia/debug/blob/953162b4fa8849268d147f4bac91c737baee55bb/browser.js#L107
In IE9 (and probably earlier versions)
typeof console.logreturnsobject. Thus no logs are ever output.