title: How do i fix in ruby on rails the undefined method `alias_method_chain' error?
body: <p>I have just cloned a github repo <a href="https://github.com/maxitron93/p2pcollective.com" rel="noreferrer">https://github.com/maxitron93/p2pcollective.com</a>, as i was exploring this awesome p2p lending app i encountered an error </p>
  
  <blockquote>
    <p>NoMethodError: undefined method `alias_method_chain' for ActiveRecord::ConnectionAdapters::PostgreSQLColumn:Class</p>
  </blockquote>
  
  <p>both when migrationg db or raunning server. I'm using the cloud9 ide to avoid my pc environment. </p>
  
  <p>Running through a couple of solution posts, i updated my gem store with device and erubis but still returned back to that 'alias_method_chain' error. </p>
  
  <p>Here's a snippet of my logs:</p>
  
  <pre><code>rake db:migrate
  rake aborted!
  NoMethodError: undefined method `alias_method_chain' for ActiveRecord::ConnectionAdapters::PostgreSQLColumn:Class
  Did you mean?  alias_method
  /usr/local/rvm/gems/ruby-2.3.4/gems/activerecord-postgres-hstore-0.7.8/lib/activerecord-postgres-hstore/activerecord.rb:80:in `&lt;class:PostgreSQLColumn&gt;'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activerecord-postgres-hstore-0.7.8/lib/activerecord-postgres-hstore/activerecord.rb:74:in `&lt;module:ConnectionAdapters&gt;'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activerecord-postgres-hstore-0.7.8/lib/activerecord-postgres-hstore/activerecord.rb:70:in `&lt;module:ActiveRecord&gt;'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activerecord-postgres-hstore-0.7.8/lib/activerecord-postgres-hstore/activerecord.rb:2:in `&lt;top (required)&gt;'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/dependencies.rb:292:in `require'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/dependencies.rb:292:in `block in require'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/dependencies.rb:256:in `block in load_dependency'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/dependencies.rb:662:in `new_constants_in'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/dependencies.rb:256:in `load_dependency'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/dependencies.rb:292:in `require'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activerecord-postgres-hstore-0.7.8/lib/activerecord-postgres-hstore/railties.rb:18:in `block (2 levels) in &lt;class:Hstore&gt;'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/lazy_load_hooks.rb:69:in `instance_eval'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/lazy_load_hooks.rb:69:in `block in execute_hook'
  /usr/local/rvm/gems/ruby-2.3.4/gems/activesupport-5.1.6/lib/active_support/lazy_load_hooks.rb:60:in `with_execution_control'
  </code></pre>
  
  <p>I expect my rails server to run smoothly from here.</p>