Is there a way to get Firefox's built-in browser console to display (or make available somehow) a complete stack trace for every error? In debugging extension code, I encounter numerous errors like "blah.blah is not a function", but without a full stack trace, I can't find out what code path led to that call.

Please note that I'm asking about the facilities built into recent versions of Firefox: in this case the browser console and "browser toolbox" (which includes a debugger, etc.). If there's a way to do this with Firebug or the like, that's great, but I'm specifically wondering here if it can be done using only the builtin tools. Also note that I'm asking about chrome code (i.e., extension code), not web page scripts (although knowing how to do it for web page scripts would also be useful info in general).


Note: This answer is only for web pages, not necessarily chrome extension code, where the question has its main focus.

Key F12 to get into Developer tools and then click in the middle toolbar on the symbol „Pause on uncaught exceptions.” (It looks like a circle with two vertical bars inside in my browser. The hover-text of the button changes after the click, see attached image.) As long as this is active, you can inspect the call stack whenever an exception occurs. To get to the next exception, resume script execution clicking the little triangle icon left of that mentioned button.

enter image description here


Consider installing FireBug (stupid min char limit)

  • 2
    I specifically stated in my question that I'm wondering whether this can be done with the builtin Firefox tools.
    – BrenBarn
    Aug 7 '14 at 1:04

I was able to enter the Debugger in developer tools to get the stack trace. I went into the Debugger settings and ticked 'Pause on exceptions'.

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