Why You Should Always Test your Add-on With Other Add-ons

Alternate Title: Personas 1.6 Breaks Add-ons

In the past couple weeks, we've started getting reports of Brand Thunder add-ons breaking. The problems range from display problems, to hangs, to the inability to bring up the add-ons manager. Of course, when you are the last add-on to be installed, you generally get the blame. After some investigating, we came across bug 590608. In case the summary isn't clear:

Personas 1.6 breaks hundreds of add-ons.

And they didn't just break add-ons. They broke the extension manager. Which means they most likely broke the ability for the broken add-on to be blocklisted. And at least a million people got this update before it was put in the sandbox.

I could probably come up with a tune kind of like Dave Carroll did when United broke his guitar, but instead I'll use this opportunity to send a message to all add-on developers (including Mozilla Corp.):

Test your add-on with other add-ons installed. Lots of other add-ons. At least the top 10. Seriously.

It will save you (and your users) a lot of pain...

And incidentally, if you want your Personas and themes to coexist without the pain that Personas 1.6 caused, get Personas Interactive.