config/initializer にこれらの行を追加しました
require 'memprof/middleware'
config.middlewares.use(Memprof::Middleware)
require 'memprof/tracer'
config.middleware.insert(0, Memprof::Tracer)
このエラーの取得
config/environments/development.rb:98:in `load_environment': undefined method `middlewares' for #<Rails::Configuration:0xb73dd47c> (NoMethodError)
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.14/lib/initializer.rb:386:in `load_environment'
from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.14/lib/active_support/core_ext/kernel/reporting.rb:11:in `silence_warnings'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.14/lib/initializer.rb:379:in `load_environment'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.14/lib/initializer.rb:137:in `process'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.14/lib/initializer.rb:113:in `send'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.14/lib/initializer.rb:113:in `run'
from /home/krunals/ms/trunk/2012-06-18-01-MangoApps/config/environment.rb:22
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:49:in `gem_original_require'
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:49:in `require'
from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:182:in `require'
from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:547:in `new_constants_in'
from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:182:in `require'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.14/lib/commands/server.rb:84
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:49:in `gem_original_require'
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:49:in `require'
from script/server:3