我在heroku上运行一个简单的rails应用程序（我的第一个）。它在本地工作正常但在打开应用程序时我有一个通用的应用程序错误。
我已经尝试过，根据其他答案，做“heroku run”“rake db：migrate”，“heroku restart”，“rake assets：precompile”，但还没有快乐。几乎只是在黑暗中拍摄。以下是日志：
heroku logs
2015-11-16T14:00:06.387026+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
2015-11-16T14:00:06.387037+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
2015-11-16T14:00:06.387049+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:180:in `each'
2015-11-16T14:00:06.387060+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
2015-11-16T14:00:06.387075+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
2015-11-16T14:00:06.387087+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/initializable.rb:54:in `run_initializers'
2015-11-16T14:00:06.387134+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:55:in `instance_eval'
2015-11-16T14:00:06.387099+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/application.rb:352:in `initialize!'
2015-11-16T14:00:06.387111+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2015-11-16T14:00:06.387123+00:00 app[web.1]: from /app/config.ru:3:in `block in <main>'
2015-11-16T14:00:06.387146+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:55:in `initialize'
2015-11-16T14:00:06.387158+00:00 app[web.1]: from /app/config.ru:in `new'
2015-11-16T14:00:06.387169+00:00 app[web.1]: from /app/config.ru:in `<main>'
2015-11-16T14:00:06.387180+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:49:in `eval'
2015-11-16T14:00:06.387191+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:49:in `new_from_string'
2015-11-16T14:00:06.387203+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:40:in `parse_file'
2015-11-16T14:00:06.387214+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:299:in `build_app_and_options_from_config'
2015-11-16T14:00:06.387226+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:208:in `app'
2015-11-16T14:00:06.387237+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/server.rb:61:in `app'
2015-11-16T14:00:06.387248+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:336:in `wrapped_app'
2015-11-16T14:00:06.387282+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:80:in `block in server'
2015-11-16T14:00:06.387259+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:272:in `start'
2015-11-16T14:00:06.387271+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/server.rb:80:in `start'
2015-11-16T14:00:06.387305+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `server'
2015-11-16T14:00:06.387293+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `tap'
2015-11-16T14:00:06.387328+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands.rb:17:in `<top (required)>'
2015-11-16T14:00:06.387316+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
2015-11-16T14:00:06.387340+00:00 app[web.1]: from bin/rails:8:in `require'
2015-11-16T14:00:06.416507+00:00 app[web.1]: => Booting WEBrick
2015-11-16T14:00:06.387352+00:00 app[web.1]: from bin/rails:8:in `<main>'
2015-11-16T14:00:06.416511+00:00 app[web.1]: => Rails 4.2.4 application starting in production on http://0.0.0.0:54745
2015-11-16T14:00:06.416512+00:00 app[web.1]: => Ctrl-C to shutdown server
2015-11-16T14:00:06.416512+00:00 app[web.1]: => Run `rails server -h` for more startup options
2015-11-16T14:00:06.416513+00:00 app[web.1]: Exiting
2015-11-16T14:00:07.129751+00:00 heroku[web.1]: Process exited with status 1
2015-11-16T14:00:07.135043+00:00 heroku[web.1]: State changed from starting to crashed
2015-11-16T15:34:27.920753+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=stormy-waters-4052.herokuapp.com request_id=5684a616-18c1-44a0-b0c9-a3b470579241 fwd="24.130.202.163" dyno= connect= service= status=503 bytes=
2015-11-16T15:34:28.434450+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=stormy-waters-4052.herokuapp.com request_id=4766d407-3879-4291-9cff-dde2c6fa600d fwd="24.130.202.163" dyno= connect= service= status=503 bytes=
2015-11-16T15:36:15.025229+00:00 heroku[web.1]: State changed from crashed to starting
2015-11-16T15:36:16.958112+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 27168 -e production`
2015-11-16T15:36:21.960104+00:00 app[web.1]: /app/app/models/ability.rb:2:in `<class:Ability>': uninitialized constant Ability::CanCan (NameError)
2015-11-16T15:36:21.960133+00:00 app[web.1]: from /app/app/models/ability.rb:1:in `<top (required)>'
2015-11-16T15:36:21.960134+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/engine.rb:472:in `block (2 levels) in eager_load!'
2015-11-16T15:36:21.960135+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/engine.rb:471:in `each'
2015-11-16T15:36:21.960136+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/engine.rb:469:in `eager_load!'
2015-11-16T15:36:21.960135+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/engine.rb:471:in `block in eager_load!'
2015-11-16T15:36:21.960136+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/engine.rb:469:in `each'
2015-11-16T15:36:21.960137+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/engine.rb:346:in `eager_load!'
2015-11-16T15:36:21.960140+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/initializable.rb:30:in `instance_exec'
2015-11-16T15:36:21.960139+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/application/finisher.rb:56:in `each'
2015-11-16T15:36:21.960140+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/application/finisher.rb:56:in `block in <module:Finisher>'
2015-11-16T15:36:21.960141+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/initializable.rb:30:in `run'
2015-11-16T15:36:21.960141+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/initializable.rb:55:in `block in run_initializers'
2015-11-16T15:36:21.960142+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
2015-11-16T15:36:21.960142+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
2015-11-16T15:36:21.960143+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
2015-11-16T15:36:21.960141+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
2015-11-16T15:36:21.960146+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:55:in `instance_eval'
2015-11-16T15:36:21.960143+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:180:in `each'
2015-11-16T15:36:21.960144+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
2015-11-16T15:36:21.960145+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/application.rb:352:in `initialize!'
2015-11-16T15:36:21.960145+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2015-11-16T15:36:21.960149+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:49:in `new_from_string'
2015-11-16T15:36:21.960175+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:299:in `build_app_and_options_from_config'
2015-11-16T15:36:21.960144+00:00 app[web.1]: from /app/vendor/ruby-2.0.0/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
2015-11-16T15:36:21.960145+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/initializable.rb:54:in `run_initializers'
2015-11-16T15:36:21.960146+00:00 app[web.1]: from /app/config.ru:3:in `block in <main>'
2015-11-16T15:36:21.960195+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:208:in `app'
2015-11-16T15:36:21.960148+00:00 app[web.1]: from /app/config.ru:in `new'
2015-11-16T15:36:21.960148+00:00 app[web.1]: from /app/config.ru:in `<main>'
2015-11-16T15:36:21.960147+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:55:in `initialize'
2015-11-16T15:36:21.960149+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:49:in `eval'
2015-11-16T15:36:21.960209+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `server'
2015-11-16T15:36:21.960208+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `tap'
2015-11-16T15:36:21.960217+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
2015-11-16T15:36:21.960198+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:272:in `start'
2015-11-16T15:36:21.960206+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/server.rb:80:in `start'
2015-11-16T15:36:21.960174+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/builder.rb:40:in `parse_file'
2015-11-16T15:36:21.960219+00:00 app[web.1]: from bin/rails:8:in `require'
2015-11-16T15:36:21.960195+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/server.rb:61:in `app'
2015-11-16T15:36:21.960197+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.6.4/lib/rack/server.rb:336:in `wrapped_app'
2015-11-16T15:36:21.960207+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:80:in `block in server'
2015-11-16T15:36:21.984658+00:00 app[web.1]: => Rails 4.2.4 application starting in production on http://0.0.0.0:27168
2015-11-16T15:36:21.960217+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-4.2.4/lib/rails/commands.rb:17:in `<top (required)>'
2015-11-16T15:36:21.984655+00:00 app[web.1]: => Booting WEBrick
2015-11-16T15:36:21.960226+00:00 app[web.1]: from bin/rails:8:in `<main>'
2015-11-16T15:36:21.984659+00:00 app[web.1]: => Run `rails server -h` for more startup options
2015-11-16T15:36:21.984660+00:00 app[web.1]: => Ctrl-C to shutdown server
2015-11-16T15:36:21.984661+00:00 app[web.1]: Exiting
2015-11-16T15:36:22.732321+00:00 heroku[web.1]: Process exited with status 1
2015-11-16T15:36:22.724457+00:00 heroku[web.1]: State changed from starting to crashed
2015-11-16T15:36:22.725695+00:00 heroku[web.1]: State changed from crashed to starting
2015-11-16T15:36:24.423653+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 19625 -e production`
2015-11-16T15:36:40.334054+00:00 heroku[run.9935]: Awaiting client
2015-11-16T15:36:40.374975+00:00 heroku[run.9935]: Starting process with command `bundle exec rake db:migrate`
2015-11-16T15:36:40.637639+00:00 heroku[run.9935]: State changed from starting to up
2015-11-16T15:36:45.450010+00:00 heroku[run.9935]: Process exited with status 0
2015-11-16T15:36:45.465182+00:00 heroku[run.9935]: State changed from up to complete
2015-11-16T15:36:37.299404+00:00 heroku[api]: Starting process with command `bundle exec rake db:migrate` by timyip1@gmail.com
2015-11-16T15:38:42.257965+00:00 heroku[router]: at=error code=H20 desc="App boot timeout" method=GET path="/" host=stormy-waters-4052.herokuapp.com request_id=fa8105d4-b55e-4f7d-a357-f86adfebbd3b fwd="24.130.202.163" dyno= connect= service= status=503 bytes=
2015-11-16T15:38:33.424916+00:00 heroku[web.1]: State changed from starting to down
答案 0 :(得分：1)
确保cancan不在Gemfile的开发块中，即如果它是这样的：
group :development do
gem "cancan"
end
将它移出那里。然后bundle install，提交Gemfile和Gemfile.lock并重新部署到heroku。