在Ruby on Rails - Heroku deployment 上，我得到了一个错误，heroku[route]: at=error code=H10 desc="App crashed" method在除错了一些日志文本之后，我得到了日志档案的主要部分：

2022-01-08T11:12:12.754916 00:00 heroku[web.1]: Starting process with command `bin/rails server -p ${PORT:-5000} -e production`
2022-01-08T11:12:16.534794 00:00 app[web.1]: => Booting Puma
2022-01-08T11:12:16.534809 00:00 app[web.1]: => Rails 6.1.4.4 application starting in production 
2022-01-08T11:12:16.534810 00:00 app[web.1]: => Run `bin/rails server --help` for more startup options
2022-01-08T11:12:17.742438 00:00 app[web.1]: Exiting
2022-01-08T11:12:17.745593 00:00 app[web.1]: /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:34:in `require': cannot load such file -- net/pop (LoadError)
2022-01-08T11:12:17.745616 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/zeitwerk-2.5.3/lib/zeitwerk/kernel.rb:35:in `require'
2022-01-08T11:12:17.745630 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/mail-2.7.1/lib/mail/network/retriever_methods/pop3.rb:36:in `<class:POP3>'
2022-01-08T11:12:17.745642 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/mail-2.7.1/lib/mail/network/retriever_methods/pop3.rb:35:in `<module:Mail>'
2022-01-08T11:12:17.745655 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/mail-2.7.1/lib/mail/network/retriever_methods/pop3.rb:4:in `<main>'
2022-01-08T11:12:17.745668 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
2022-01-08T11:12:17.745681 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
2022-01-08T11:12:17.745694 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
2022-01-08T11:12:17.745708 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
2022-01-08T11:12:17.745720 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
2022-01-08T11:12:17.745733 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/zeitwerk-2.5.3/lib/zeitwerk/kernel.rb:35:in `require'
2022-01-08T11:12:17.745745 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/mail-2.7.1/lib/mail.rb:54:in `block in eager_autoload!'
2022-01-08T11:12:17.745761 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/mail-2.7.1/lib/mail.rb:54:in `each'
2022-01-08T11:12:17.745774 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/mail-2.7.1/lib/mail.rb:54:in `eager_autoload!'
2022-01-08T11:12:17.745786 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/actionmailer-6.1.4.4/lib/action_mailer.rb:61:in `eager_load!'
2022-01-08T11:12:17.745799 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/application/finisher.rb:134:in `each'
2022-01-08T11:12:17.745811 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/application/finisher.rb:134:in `block in <module:Finisher>'
2022-01-08T11:12:17.745824 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/initializable.rb:32:in `instance_exec'
2022-01-08T11:12:17.745838 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/initializable.rb:32:in `run'
2022-01-08T11:12:17.745850 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/initializable.rb:61:in `block in run_initializers'
2022-01-08T11:12:17.745863 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:228:in `block in tsort_each'
2022-01-08T11:12:17.745875 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
2022-01-08T11:12:17.745888 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:431:in `each_strongly_connected_component_from'
2022-01-08T11:12:17.745900 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:349:in `block in each_strongly_connected_component'
2022-01-08T11:12:17.745913 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:347:in `each'
2022-01-08T11:12:17.745926 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:347:in `call'
2022-01-08T11:12:17.745938 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:347:in `each_strongly_connected_component'
2022-01-08T11:12:17.745950 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:226:in `tsort_each'
2022-01-08T11:12:17.745963 00:00 app[web.1]:    from /app/vendor/ruby-3.1.0/lib/ruby/3.1.0/tsort.rb:205:in `tsort_each'
2022-01-08T11:12:17.745975 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/initializable.rb:60:in `run_initializers'
2022-01-08T11:12:17.745988 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/application.rb:391:in `initialize!'
2022-01-08T11:12:17.746002 00:00 app[web.1]:    from /app/config/environment.rb:5:in `<main>'
2022-01-08T11:12:17.746015 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
2022-01-08T11:12:17.746027 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
2022-01-08T11:12:17.746040 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
2022-01-08T11:12:17.746053 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
2022-01-08T11:12:17.746066 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
2022-01-08T11:12:17.746079 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/zeitwerk-2.5.3/lib/zeitwerk/kernel.rb:35:in `require'
2022-01-08T11:12:17.746092 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.4.4/lib/active_support/dependencies.rb:332:in `block in require'
2022-01-08T11:12:17.746104 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.4.4/lib/active_support/dependencies.rb:299:in `load_dependency'
2022-01-08T11:12:17.746117 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/activesupport-6.1.4.4/lib/active_support/dependencies.rb:332:in `require'
2022-01-08T11:12:17.746130 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:54:in `require_relative'
2022-01-08T11:12:17.746143 00:00 app[web.1]:    from config.ru:3:in `block in <main>'
2022-01-08T11:12:17.746156 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/builder.rb:116:in `eval'
2022-01-08T11:12:17.746169 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/builder.rb:116:in `new_from_string'
2022-01-08T11:12:17.746181 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/builder.rb:105:in `load_file'
2022-01-08T11:12:17.746194 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/builder.rb:66:in `parse_file'
2022-01-08T11:12:17.746206 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/server.rb:349:in `build_app_and_options_from_config'
2022-01-08T11:12:17.746219 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/server.rb:249:in `app'
2022-01-08T11:12:17.746232 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/server.rb:422:in `wrapped_app'
2022-01-08T11:12:17.746245 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/server.rb:312:in `block in start'
2022-01-08T11:12:17.746258 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/server.rb:379:in `handle_profiling'
2022-01-08T11:12:17.746270 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/rack-2.2.3/lib/rack/server.rb:311:in `start'
2022-01-08T11:12:17.746283 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/commands/server/server_command.rb:39:in `start'
2022-01-08T11:12:17.746297 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/commands/server/server_command.rb:144:in `block in perform'
2022-01-08T11:12:17.746309 00:00 app[web.1]:    from <internal:kernel>:90:in `tap'
2022-01-08T11:12:17.746322 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/commands/server/server_command.rb:135:in `perform'
2022-01-08T11:12:17.746335 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/thor-1.2.1/lib/thor/command.rb:27:in `run'
2022-01-08T11:12:17.746348 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/thor-1.2.1/lib/thor/invocation.rb:127:in `invoke_command'
2022-01-08T11:12:17.746361 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/thor-1.2.1/lib/thor.rb:392:in `dispatch'
2022-01-08T11:12:17.746373 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/command/base.rb:69:in `perform'
2022-01-08T11:12:17.746386 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/command.rb:48:in `invoke'
2022-01-08T11:12:17.746399 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/railties-6.1.4.4/lib/rails/commands.rb:18:in `<main>'
2022-01-08T11:12:17.746412 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
2022-01-08T11:12:17.746424 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
2022-01-08T11:12:17.746437 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/loaded_features_index.rb:100:in `register'
2022-01-08T11:12:17.746451 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
2022-01-08T11:12:17.746463 00:00 app[web.1]:    from /app/vendor/bundle/ruby/3.1.0/gems/bootsnap-1.9.3/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
2022-01-08T11:12:17.746476 00:00 app[web.1]:    from bin/rails:5:in `<main>'
2022-01-08T11:12:17.961296 00:00 heroku[web.1]: Process exited with status 1
2022-01-08T11:12:18.044550 00:00 heroku[web.1]: State changed from starting to crashed

虽然这是生产环境日志全文的主题，但是在本地开发环境中，启动Rails服务器时没有发现问题！在开发环境中一切正常。

此外，该 URL 显示以下文本：

Application error An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details. You can do this from the Heroku CLI with the command heroku logs --tail

And the console is showing this: Failed to load resource: the server responded with a status of 503 (Service Unavailable)

uj5u.com热心网友回复：

解决方案

好的，在修复了从日志档案中发现的错误的几次部署之后，我知道，在我们的Gemfile 中，我们需要添加一些依赖项所需的gem（大约 3 个 gem）。这些宝石是：

# Gemfile

gem 'net-smtp', require: false
gem 'net-pop', require: false
gem 'net-imap', require: false

将它们添加到我们的 gem 档案后，运行

bundle install

然后在heroku上部署代码，这将进行正确的部署。