memory leak gone for real

config/environments/development.rb

@@ -1,3 +1,4 @@
+require 'lib/mongo_mapper/clear_dev_memory'
 Diaspora::Application.configure do
   # Settings specified here will take precedence over those in config/environment.rb
 
@@ -17,5 +18,6 @@ Diaspora::Application.configure do
   # Don't care if the mailer can't send
   config.action_mailer.raise_delivery_errors = false
   config.active_support.deprecation = :log
+  config.middleware.use MongoMapper::ClearDevMemory
   #config.threadsafe!
 end

lib/mongo_mapper/clear_dev_memory.rb

@@ -1,5 +1,5 @@
 module MongoMapper
-  class PerRequestMapClear
+  class ClearDevMemory
     def initialize(app)
       @app = app
     end