title: undefined method `alias_method_chain' in active record 3.2.18 without rails migration
body: <p>This is my Rakefile</p>
  
  <pre><code>require 'bundler'
  Bundler.setup
  require 'active_record'
  require 'sqlite3'
  require 'yaml'
  require 'logger'
  
  task :migrate =&gt; :environment do
     ActiveRecord::Migrator.migrate('db/migrate', ENV["VERSION"] ? ENV["VERSION"].to_i : nil )
  end
  
  task :environment do
    ActiveRecord::Base.establish_connection(YAML::load(File.open('config/database.yaml'))['development'])
    ActiveRecord::Base.logger = Logger.new(STDOUT)
  end
  </code></pre>
  
  <p>When I execute the task I got this error:</p>
  
  <pre><code>rake aborted!
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:2449: warning: already initialized constant Class::VALID_FIND_OPTIONS
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:2449: warning: previous definition of VALID_FIND_OPTIONS was here
  undefined method `alias_method_chain' for #&lt;Class:0x00000001606340&gt;
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:2002:in `method_missing'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/validations.rb:387:in `block in included'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/validations.rb:386:in `class_eval'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/validations.rb:386:in `included'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:3210:in `include'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:3210:in `block in &lt;module:ActiveRecord&gt;'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:3208:in `class_eval'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:3208:in `&lt;module:ActiveRecord&gt;'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/activerecord-2.3.18/lib/active_record/base.rb:5:in `&lt;top (required)&gt;'
  /home/marco/desenv/technical_analysis/Rakefile:14:in `block in &lt;top (required)&gt;'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
  /usr/local/rvm/gems/ruby-2.0.0-p0@ta/gems/rake-10.0.4/lib/rake/task.rb:246:in `block in execute'
  </code></pre>
  
  <p>I had some debug and some test... <strong>Then i moved to 3.2.13</strong> version of active record, and all worked as expected. I didn't find any docs for 3.2.18 version...</p>
  
  <p>I don't mind to use 3.2.13 version, but I got curious about that. </p>