ruby on rails - Cannot deploy my application on Heroku -

i cant deploy application on heroku tried alot no luck ! , have tried bundle update not working

application error  error occurred in application , page not served. please try again in few moments.  if application owner, check logs details. 

in gemfile added gem 'devise' , gem 'cancan' under gem 'rails' , ruby '1.9.3' above gem 'rails'

application.rb

require file.expand_path('../boot', __file__)  require 'rails/all' require 'devise'       config.assets.initialize_on_precompile = false 

when git push heroku master, see following during pushing

preparing app rails asset pipeline        running: rake assets:precompile        rake aborted!        not connect server: connection refused        server running on host "127.0.0.1" , accepting        tcp/ip connections on port 5432?        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `initialize'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `new'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `connect'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:326:in `initialize'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checkout_new_connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block (2 levels) in checkout'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/model_schema.rb:308:in `clear_cache!'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activerecord-3.2.12/lib/active_record/railtie.rb:97:in `block (2 levels) in <class:railtie>'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:418:in `_run__1823897648455200442__prepare__4158920102365195865__callbacks'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:405:in `__run_callback'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:81:in `run_callbacks'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.12/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.12/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application/finisher.rb:47:in `block in <module:finisher>'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `instance_exec'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `run'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:55:in `block in run_initializers'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `each'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `run_initializers'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:136:in `initialize!'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30:in `method_missing'        /tmp/build_2avqf4cxqc1b9/config/environment.rb:5:in `<top (required)>'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/dependencies.rb:251:in `require'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/dependencies.rb:251:in `block in require'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/dependencies.rb:236:in `load_dependency'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.12/lib/active_support/dependencies.rb:251:in `require'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:103:in `require_environment!'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:297:in `block (2 levels) in initialize_tasks'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.12/lib/sprockets/assets.rake:93:in `block (2 levels) in <top (required)>'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.12/lib/sprockets/assets.rake:60:in `block (3 levels) in <top (required)>'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.12/lib/sprockets/assets.rake:23:in `invoke_or_reboot_rake_task'        /tmp/build_2avqf4cxqc1b9/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.12/lib/sprockets/assets.rake:29:in `block (2 levels) in <top (required)>'        tasks: top => environment        (see full trace running task --trace)        precompiling assets failed, enabling runtime asset compilation        injecting rails31_enable_runtime_asset_compilation        please see article troubleshooting help:        http://devcenter.heroku.com/articles/rails31_heroku_cedar#troubleshooting -----> warnings:        have not declared ruby version in gemfile.        set ruby version add line gemfile:        ruby '2.0.0' 

after type heroku run rake db:migrate, following

running `rake db:migrate` attached terminal... up, run.4282 deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/rakefile:7) deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/rakefile:7) deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/rakefile:7) rake aborted! uninitialized constant devise /app/config/initializers/devise.rb:3:in `<top (required)>' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:588:in `block (2 levels) in <class:engine>' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `each' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `block in <class:engine>' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `instance_exec' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `run' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:55:in `block in run_initializers' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `each' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `run_initializers' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:136:in `initialize!' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30:in `method_missing' /app/config/environment.rb:5:in `<top (required)>' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:103:in `require_environment!' /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:297:in `block (2 levels) in initialize_tasks' tasks: top => db:migrate => environment (see full trace running task --trace) 

update: have added config.assets.initialize_on_precompile = false application.rb instead of production.rb

git remote -v heroku  git@heroku.com:nameless-lowlands-8457.git (fetch) heroku  git@heroku.com:nameless-lowlands-8457.git (push) origin  git://github.com/code-vortex/triton.git (fetch) origin  git://github.com/code-vortex/triton.git (push) 

but posted here not updated in repo , consider backup.

heroku logs

2013-08-13t01:23:51.447646+00:00 heroku[web.1]: starting process command `bundle exec thin start -r config.ru -e $rails_env -p 13441` 2013-08-13t01:23:56.478911+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:23:56.479632+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:23:56.479271+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:24:02.134733+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `run' 2013-08-13t01:24:02.135708+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30:in `method_missing' 2013-08-13t01:24:02.134384+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `block in <class:engine>' 2013-08-13t01:24:02.134052+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:588:in `block (2 levels) in <class:engine>' 2013-08-13t01:24:02.134254+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `each' 2013-08-13t01:24:02.133824+00:00 app[web.1]: /app/config/initializers/devise.rb:3:in `<top (required)>': uninitialized constant devise (nameerror) 2013-08-13t01:24:02.134534+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `instance_exec' 2013-08-13t01:24:02.135363+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `run_initializers' 2013-08-13t01:24:02.136273+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize' 2013-08-13t01:24:02.135909+00:00 app[web.1]:    /app/config/environment.rb:5:in `<top (required)>' 2013-08-13t01:24:02.136004+00:00 app[web.1]:    config.ru:3:in `require' 2013-08-13t01:24:02.135503+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:136:in `initialize!' 2013-08-13t01:24:02.134996+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `each' 2013-08-13t01:24:02.136646+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/rack/adapter/loader.rb:33:in `load' 2013-08-13t01:24:02.134876+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:55:in `block in run_initializers' 2013-08-13t01:24:02.136360+00:00 app[web.1]:    config.ru:1:in `new' 2013-08-13t01:24:02.136841+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/controllers/controller.rb:71:in `start' 2013-08-13t01:24:02.136451+00:00 app[web.1]:    config.ru:1:in `<main>' 2013-08-13t01:24:02.136556+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/rack/adapter/loader.rb:33:in `eval' 2013-08-13t01:24:02.137239+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/bin/thin:23:in `load' 2013-08-13t01:24:02.136185+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval' 2013-08-13t01:24:02.136094+00:00 app[web.1]:    config.ru:3:in `block in <main>' 2013-08-13t01:24:02.136930+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/runner.rb:187:in `run_command' 2013-08-13t01:24:02.136735+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/controllers/controller.rb:181:in `load_rackup_config' 2013-08-13t01:24:02.137143+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/bin/thin:6:in `<top (required)>' 2013-08-13t01:24:02.137332+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/bin/thin:23:in `<main>' 2013-08-13t01:24:02.137021+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/runner.rb:152:in `run!' 2013-08-13t01:24:05.560278+00:00 heroku[web.1]: process exited status 1 2013-08-13t01:24:05.580273+00:00 heroku[web.1]: state changed starting crashed 2013-08-13t01:34:05.701049+00:00 heroku[web.1]: state changed crashed starting 2013-08-13t01:34:11.421800+00:00 heroku[web.1]: starting process command `bundle exec thin start -r config.ru -e $rails_env -p 13652` 2013-08-13t01:34:14.284915+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:34:14.284557+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:34:14.284661+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `each' 2013-08-13t01:34:14.565803+00:00 app[web.1]: /app/config/initializers/devise.rb:3:in `<top (required)>': uninitialized constant devise (nameerror) 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `instance_exec' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:588:in `block (2 levels) in <class:engine>' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `block in <class:engine>' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:136:in `initialize!' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    config.ru:3:in `block in <main>' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `each' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    /app/config/environment.rb:5:in `<top (required)>' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30:in `method_missing' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `run_initializers' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:55:in `block in run_initializers' 2013-08-13t01:34:14.565803+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `run' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    config.ru:3:in `require' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    config.ru:1:in `new' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    config.ru:1:in `<main>' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/rack/adapter/loader.rb:33:in `eval' 2013-08-13t01:34:14.566134+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/rack/adapter/loader.rb:33:in `load' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/bin/thin:23:in `<main>' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/controllers/controller.rb:71:in `start' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/controllers/controller.rb:181:in `load_rackup_config' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/bin/thin:6:in `<top (required)>' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/runner.rb:187:in `run_command' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/bin/thin:23:in `load' 2013-08-13t01:34:14.566435+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/runner.rb:152:in `run!' 2013-08-13t01:34:15.747785+00:00 heroku[web.1]: process exited status 1 2013-08-13t01:34:15.761595+00:00 heroku[web.1]: state changed starting crashed 2013-08-13t01:44:17.844153+00:00 heroku[web.1]: state changed crashed starting 2013-08-13t01:44:24.693053+00:00 heroku[web.1]: starting process command `bundle exec thin start -r config.ru -e $rails_env -p 25419` 2013-08-13t01:44:29.788435+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:44:29.788776+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:44:29.788028+00:00 app[web.1]: deprecation warning: have rails 2.3-style plugins in vendor/plugins! support these plugins removed in rails 4.0. move them out , bundle them in gemfile, or fold them in app lib/myplugin/* , config/initializers/myplugin.rb. see release notes more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called <top (required)> @ /app/config/environment.rb:5) 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:588:in `block (2 levels) in <class:engine>' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `instance_exec' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `each' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/engine.rb:587:in `block in <class:engine>' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:55:in `block in run_initializers' 2013-08-13t01:44:30.423027+00:00 app[web.1]: /app/config/initializers/devise.rb:3:in `<top (required)>': uninitialized constant devise (nameerror) 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval' 2013-08-13t01:44:30.423252+00:00 app[web.1]:    config.ru:3:in `require' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `each' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:54:in `run_initializers' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/application.rb:136:in `initialize!' 2013-08-13t01:44:30.423252+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30:in `method_missing' 2013-08-13t01:44:30.423252+00:00 app[web.1]:    /app/config/environment.rb:5:in `<top (required)>' 2013-08-13t01:44:30.423252+00:00 app[web.1]:    config.ru:3:in `block in <main>' 2013-08-13t01:44:30.423027+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.12/lib/rails/initializable.rb:30:in `run' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    config.ru:1:in `new' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/runner.rb:187:in `run_command' 2013-08-13t01:44:30.423661+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/bin/thin:6:in `<top (required)>' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    config.ru:1:in `<main>' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/rack/adapter/loader.rb:33:in `eval' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/rack/adapter/loader.rb:33:in `load' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/controllers/controller.rb:181:in `load_rackup_config' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/runner.rb:152:in `run!' 2013-08-13t01:44:30.423661+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/bin/thin:23:in `<main>' 2013-08-13t01:44:30.423511+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/gems/thin-1.5.1/lib/thin/controllers/controller.rb:71:in `start' 2013-08-13t01:44:30.423661+00:00 app[web.1]:    /app/vendor/bundle/ruby/2.0.0/bin/thin:23:in `load' 2013-08-13t01:44:31.948656+00:00 heroku[web.1]: process exited status 1 2013-08-13t01:44:31.971770+00:00 heroku[web.1]: state changed starting crashed 

try changing initialize_on_precompile configuration false in application.rb file so:

config.assets.initialize_on_precompile = false 

source: http://www.simonecarletti.com/blog/2012/02/heroku-and-rails-3-2-assetprecompile-error/