I ended up removing all four addons from my system (since they seem to be unmaintained and/or deprecated); here are the package names:
xul-ext-ubufox - Ubuntu modifications for Firefox xul-ext-unity - Firefox extension: Unity Integration xul-ext-webaccounts - Ubuntu Online Accounts extension for firefox xul-ext-websites-integration - Firefox extension: Website Integration -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1069793 Title: Can't install search engines (Tramples over window.external) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity-firefox-extension/+bug/1069793/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
