Development Blog

Firebug bugs vs Firefox bugs

I’m having deja vu all over again. Last spring we spent several months to get Firebug 1.2 to work on Firefox 3.0. This included completely re-writing the Firebug console and command line among other issues.   At the time I chalked this up to the big jump from FF 2.0 to FF 3.0. Now I can see this was the wrong way to look at it.

We are now trying to get Firebug 1.4 working on Firefox 3.5.  We’ve worked around two bugs,  484459 and 485055, and are only blocked by one at the present time (483672).  This does not seem so bad, except that we also have separate bug to fight with Firefox 3.0.7 (bug 482293) one that causes Firebug 1.3.3 to hang on pages with things like google maps.  We don’t have a resolution for this and our workaround in Firebug 1.3.4b2 breaks other things.

But if we step back and review our position, it’s not good. While we are spending time on new Firebug features and Firefox bugs, but we are not fixing existing Firebug bugs.   Moreover, debuggers should be available when systems are in alpha phase, but Firefox 3.5 is almost completely finished before Firebug can work with it.

So what can we do?

One option we cannot adopt is to develop Firebug on the Firefox trunk (now Firefox 3.6).  I’ve tried that in the past and it’s a nightmare. Firebug touches almost every part of Firefox so it almost never works on nightly builds for long. With Firefox 3.1 it wasn’t until b3 that enough stuff worked for us to start. Before that every effort to debug Firebug is a compounded by uncertainty in the underlying platform.

But we do have another option, based on three changes since last spring.  First, the Firefox team has been extraordinarily helpful with Firebug issues, once we are able to express a problem in Firefox terms.  Second we finally have a Firebug test system. And third, Honza and I can build Firefox now so we are better able to communicate our issues (which originate in Javascript)  to the Firefox team (which thinks primarily in C++).

So our plan is for Robcee to work towards automatically running the ‘passing’ Firebug Tests on the nightly trunk builds.  After we can succeed once, we hope that we can alert the Firefox team of problems that impact Firebug within a few days of their appearance, while the issues are still fresh in the developers heads. That way we can keep Firebug running rather than falling behind.


9 Responses to “Firebug bugs vs Firefox bugs”

  1. Boris Says:

    Do those tests depend on Firebug per se being installed? Or could they be turned into mochitests, etc, and run on tbox?

  2. johnjbarton Says:

    Eventually we hope to have a firebug test suite as part of the unit tests for Firefox. But we need to have some experience with doing our tests routinely before we inflict them on the Firefox committers ;-).

  3. ~robcee/ » Blog Archive » Firebug and 3.5 compatibility Says:

    […] had getting Firebug working with Firefox 3.5 over the last couple of months in a separate blog post on the […]

  4. johnjbarton Says:

    Boris, all of the FBTests require Firebug (I’m not sure about the per se part ;-). There is a quick outline of how they work linked in the blog post under Firebug Test System. The system that can be launched from the FF command line and emit results to the OS stdout (window.dump()). If this turns out to be a bad match for Firefox testing, I think we will be able to pick a few key tests and make them mochitests.

  5. johnjbarton Says:

    @shaver: Firefox can remain usable on its own code base because developers test Firefox as they commit code to it. If they also tested Firebug then of course we would be able to keep up. That is what we are working towards.

    I don’t understand how we could change Firebug in the way you suggest. We can’t develop code for APIs that don’t exist, we have a hard enough time with those that do! We have submitted bugs requesting changes to error handling (435025), loading (342715), caching (484710), and javascript debugging (449452). What else can we do?

  6. James Dempster Says:

    Wow sounds like to really difficult issues to work with.
    Appreciate all the hard work you guys put into this!

  7. Craig Buchan Says:

    I have to hand it to you guys, I love firebug and if it were not for your hard work my web development would be an absolute nightmare! Since I got Firebug I binned dreamweaver completely!

    Keep up the top work!

  8. Jim Says:

    Couldn’t find an email to report bugs to so excuse me for posting here. My browser crashes with a segfault every time I visit

    I’m using Firefox 3.0.10 on Ubuntu (9.04). Firebug extension is version 1.3.3. With the Firebug extension disabled, things seem to be OK.

    With Firebug enabled, clearing the cache also seems to work, but only for a few page reloads. After a while it will start crashing again. Sudden and brutal crashes.

    Hope this finds the right audience, and hope the feedback helps.

  9. johnjbarton Says:

    Please post bug report to or the newgroup, We’ll tell you to contact Firefox, but may be we can help a little.