The hoptoad_notifier gem is not updated to work with Ruby 1.9.2 yet, the following error will occur:
NoMethodError (private method `params_filters=` called for
#<HoptoadNotifier::Notice:0x000001041b0dc8>):
As discussed in this Lighthouse ticket, they are still working on official 1.9.2 support, in the meantime, there are a couple of forks to get you going. I’m using this version by Rich Cavanaugh that works well.
I’ve forked that one myself and added a .gemspec for easy integration in a Gemfile, just drop this in and you’re on your way!
gem 'hoptoad_notifier', :git =>
'http://github.com/bittersweet/hoptoad_notifier'