build_record

# File activerecord/lib/active_record/associations/association.rb, line 233
        def build_record(attributes, options)
          reflection.original_build_association_called = false

          record = reflection.build_association(attributes, options) do |r|
            r.assign_attributes(
              create_scope.except(*r.changed),
              :without_protection => true
            )
          end

          if !reflection.original_build_association_called &&
             (record.changed & create_scope.keys) != create_scope.keys
            # We have detected that there is an overridden AssociationReflection#build_association
            # method, but it looks like it has not passed through the block above. So try again and
            # show a noisy deprecation warning.

            record.assign_attributes(
              create_scope.except(*record.changed),
              :without_protection => true
            )

            method = reflection.method(:build_association)
            if RUBY_VERSION >= '1.9.2'
              source = method.source_location
              debug_info = "It looks like the method is defined in #{source[0]} at line #{source[1]}."
            else
              debug_info = "This might help you find the method: #{method}. If you run this on Ruby 1.9.2 we can tell you exactly where the method is."
            end

            ActiveSupport::Deprecation.warn It looks like ActiveRecord::Reflection::AssociationReflection#build_association has been redefined, either by you or by a plugin or library that you are using. The signature of this method has changed.  Before: def build_association(*options)  After:  def build_association(*options, &block)The block argument now needs to be passed through to ActiveRecord::Base#new when this method is overridden, or else your associations will not function correctly in Rails 3.2.#{debug_info}
          end

          record
        end