As part of yesterday’s Firefox 10th anniversary celebrations, we released a new special version of Firefox, version 33.1. Since it was meant to be a surprise release, it didn’t ride the trains in the same way as other features and it ended up unexpectedly breaking things for some add-ons.
The new Forget button
There’s a new button in the toolbar palette. It doesn’t appear in the toolbar by default, but you can see it if you enter customization mode. Unexpected buttons can break complete themes and this case is no exception. The solution is to update the theme to support this new button.
Binary XPCOM and version numbers
Binary XPCOM is a legacy technology that we hope to phase out of add-ons soon, in favor of JS ctypes and other pure JS solutions. Current support for binary XPCOM in add-ons is clunky at best, and developers need to rebuild their components for every new major version of Firefox.
After the 33.1 release, we discovered some add-ons doing this in their chrome.manifest files:
interfaces components/component33.xpt appversion=33.0 appversion=33.0.1 appversion=33.0.2 appversion=33.0.3 ...
This allows developers to have components built for various Firefox versions in the same add-on package, and declare which components need to be loaded for which Firefox version. However, since this doesn’t contemplate 33.1, no components are being loaded for that version. The easier solution in this case is just to add 33.1 to that list (33.1 is binary-compatible with the regular 33 branch). I’m fairly sure we won’t have any more surprise releases before we discontinue binary XPCOM, so I don’t think a more robust solution is needed. Update: however, please note there’s already a 31.1.1 and there could be other 31.1.* updates.
I’m sorry for the last-minute inconvenience, but hopefully the fixes are easy enough that you can issue quick updates for your add-ons and most of your users aren’t affected. If your add-on is on AMO, feel free to contact us to the amo-editors list or me directly so we can prioritize your compatibility updates.