从头开始重新开发一个应用程序？(Re-developing an app from scratch?)

 我终于找到了问题的根源。 结论是当没有任何自定义类的vanilla Rails应用程序中发生状态错误（404,500等）时，Heroku将提供基本错误页面。 在我确定之后，它有助于指导诊断。 
 
 通过config / environments / staging.rb代码，我看到他们的文档中规定的sentry-raven的LOC应设置为false： 
 
config.action_dispatch.show_exceptions = false #per sentry-raven docs
 
 将此设置恢复为true后，状态错误页面开始运行： 
 
config.action_dispatch.show_exceptions = true #status error pages work again!
 
 所以，我可能误解了哨兵乌鸦的文档并将其错误地合并到Rails应用程序配置中，或其他方面，但这就是问题的结果。 所以，如果您的Heroku托管Rails应用程序运行良好，然后在任何状态错误时遇到“死亡白屏”，这是检查您的诊断尝试的另一件事。 

I finally got to the bottom of the issue. The conclusion is that Heroku will serve the basic error pages when a status error (404, 500, etc) happens in a vanilla Rails application without any custom classes. After I determined that, it helped direct the diagnosis. 
 
Looking through the config/environments/staging.rb code, I saw the LOC that sentry-raven stipulated in their docs should be set to false:
 
config.action_dispatch.show_exceptions = false #per sentry-raven docs
 
After setting this back to true, the status error pages started functioning:
 
config.action_dispatch.show_exceptions = true #status error pages work again!
 
So, I may have been misunderstanding sentry-raven's docs & incorporating it incorrectly into the Rails app configs, or something otherwise, but that's what the issue turned out to be. So, if you your Heroku hosted Rails app is performing fine and then runs into the "white screen of death" upon any status error, this is one more thing to check in your attempts to diagnose.