Ticket at #1194
As first described on Rails talk, script/console -s gives the error:
.../vendor/rails/activerecord/lib/active_record/base.rb:1824:in `method_missing':NoMethodError: undefined method `increment_open_transactions' for ActiveRecord::Base:Class
on Edge. I’ll also add that it doesn’t roll back transactions.
Ticket has a patch - very simple. Should probably go in 2.2, as the current version is dangerous (not rolling back).