# put this in lib/nil_store.rb:

class NilStore < ActiveSupport::Cache::Store

  def initialize(location='//myloc'); end

  def read(name, options = nil); super; end

  def write(name, value, options = nil); super; end

  def delete(name, options = nil); super; end

  def delete_matched(matcher, options = nil); super; end

end

# and then in environments/development.rb:

require 'nil_store'
config.cache_store = NilStore.new

# or you could just turn on development class caching:

config.cache_classes = true