title: Hunting down: DEPRECATION WARNING: Database connections will not be closed automatically
body: <p>I've got this trace and no idea how to trace down the cause for this. this is popping up during tests running. Any ideas on how to proceed?</p>
  
  <pre><code>DEPRECATION WARNING: Database connections will not be closed automatically, please close your
  database connection at the end of the thread by calling `close` on your
  connection.  For example: ActiveRecord::Base.connection.close
  . (called from mon_synchronize at /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211)
  /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:212:in `block in clear_stale_cached_connections!'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:210:in `each'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:210:in `clear_stale_cached_connections!'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:274:in `block (2 levels) in checkout'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/query_cache.rb:61:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/callbacks.rb:405:in `_run__1441209721629762293__call__222931449678172199__callbacks'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/callbacks.rb:405:in `__run_callback'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/callbacks.rb:81:in `run_callbacks'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/rack/logger.rb:32:in `call_app'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/rack/logger.rb:16:in `block in call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/tagged_logging.rb:22:in `tagged'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/rack/logger.rb:16:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/request_id.rb:22:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/methodoverride.rb:21:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/runtime.rb:17:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/lock.rb:15:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/actionpack-3.2.9/lib/action_dispatch/middleware/static.rb:62:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/airbrake-3.1.6/lib/airbrake/rack.rb:41:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/airbrake-3.1.6/lib/airbrake/user_informer.rb:12:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/engine.rb:479:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/railties-3.2.9/lib/rails/application.rb:223:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/builder.rb:134:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/urlmap.rb:64:in `block in call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/urlmap.rb:49:in `each'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/urlmap.rb:49:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/capybara-1.1.3/lib/capybara/server.rb:17:in `call'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/rack-1.4.5/lib/rack/handler/webrick.rb:59:in `service'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
    /home/gaul/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
  </code></pre>