Sentry-ruby: Exceptions not sent to Sentry from development environment (better_errors)

[shrirambalakrishnan]

In development environment, only when exception is captured explicitly using Raven.capture, the exception is getting sent to Sentry and shown in the list of exceptions.

But if config.consider_all_requests_local = false in development.rb, the exceptions are sent.

Related issue - https://github.com/getsentry/raven-ruby/issues/202

Gem versions:
rails-4.2.7.1
sentry-raven-2.6.2

[nateberkopec]

I'm going to need some additional reproduction steps. Using a blank "rails new" application in development (so config.consider_all_requests_local = true), I can successfully raise and capture exceptions w/Sentry, e.g.:

class HelloController < ApplicationController
  def exception
    raise "Hi!"
  end
end

[nateberkopec]

You can try modifying this script to reproduce your issue.

[irobayna]

@nateberkopec Same here with an Ruby on Rails API, I do see upon startup

INFO -- sentry: ** [Raven] Raven 2.6.3 ready to catch errors

specs:

Rails 5.1.3
Puma 3.9.1
Ruby 2.4.1-p111

BTW, if I send a command to capture message that works:

Raven.capture_message("Something went very wrong")

Your example above does not...

[nateberkopec]

Please feel free to reopen with reproduction steps.

[D1ceWard]

I have same problem and for me it's caused by better_errors gem.

Simply add better_errors gem to your script to reproduce.

[punitcse]

I also have the same issue using
rails 5.2
sentry-raven-2.7.4

[kerwin-personalyze]

Hi, I also encountered the same issue.
I don't have better_errors gem in my project.

What I did was to declare this in my controller

      def index
        1/0
      end

and have the following set in my sentry.rb

Raven.configure do |config|
  config.dsn = *******
  config.sanitize_fields = Rails.application.config.filter_parameters.map(&:to_s)
  config.environments = %w[development]
  config.excluded_exceptions = []
end

If I invoke Raven.send_capture(), then it works.

[brutuscat]

Hello, I stumbled against this "conflict" with the BetterErrors middleware too. IMHO, given that the BetterErrors middleware is inserted after the DebugExceptions and exceptions for some reason never reach DebugExceptions (is as if the bubbling goes the other way in the stack?), maybe we should consider either monkey patching the BetterErrors::Middleware#protected_app_call or move the Rack middleware to the end instead that at the beginning.

[silent-e]

I'm seeing this issue as well and I can reproduce the weirdness 100% of the time in my development env. With better_errors installed Raven does not capture the error. Without better_errors enabled, the error is captured.

As better_errors is more important to me in the development environment I'm just going to disable Raven in dev.

(e)

[alphabt]

+1. Would be nice to have this be compatible with better_errors.

[cjlarose]

Raven inserts its middleware, Raven::Rack, in the first (outermost) position. This is desirable because it catches any exceptions that bubble up, especially those that happen in the middleware stack itself.

BetterErrors inserts its middleware, BetterErrors::Middleware, just after DebugExceptions, if it is defined. In the PR that put it there, it's mentioned that this is nice since BetterErrors will render a page for exceptions that originate in all middlewares that are _after_ DebugExceptions. It must be after DebugExceptions itself, however, since DebugExceptions would otherwise swallow the exception before BetterErrors could access it.

In order to prevent DebugExceptions from swallowing the exception, Raven instead patches ActionDispatch::DebugExceptions and ActionDispatch::ShowExceptions in that way that makes it so that errors are reported to Sentry first before rendering the error page.

So, one way to add compatibility for BetterErrors to Raven is to patch BetterErrors::Middleware in a similar way that Raven currently does to ActionDispatch::DebugExcecptions and ActionDispatch::ShowExceptions.

In a Rails initializer,

# https://github.com/getsentry/raven-ruby/issues/738#issuecomment-592720365
if defined?(::BetterErrors::Middleware)
  module BetterErrorsRavenCompatibility
    def show_error_page(env, exception = nil)
      begin
        Raven::Rack.capture_exception exception, env if exception
      rescue StandardError # rubocop:disable Lint/HandleExceptions
      end

      super
    end
  end

  Rails.application.config.after_initialize do
    if Raven.configuration.rails_report_rescued_exceptions
      BetterErrors::Middleware.prepend BetterErrorsRavenCompatibility
    end
  end
end

This works, but since it's basically a monkey-patch to BetterErrors, it relies on private API that might change between versions.

It's not clear what the best long-term fix is, though. It doesn't really make sense for BetterErrors to automatically detect Raven and to automatically report the error. Similarly, I could understand if maintainers of Raven didn't want to add custom code for maintaining BetterErrors support.

The right fix might just be to add documentation for Raven somewhere that includes a patch like this.

[nateberkopec]

@cjlarose I don't maintain this anymore (someone else at Sentry does) but just wanted to leave a comment: you leave some of the amazingly clear and detailed explanations of bugs on OSS repos that I have ever seen.

[sedubois]

We encounter the same issue in our app with better_errors (for now we use the mentioned workaround, thanks!).

@st0012 what is the intended solution considering the "wontfix" label added on Sep 17?

[st0012]

this is not really a sentry SDK's issue imo (nor better_error's though).

this kind of issue can happen when any Ruby gem's middleware tries to rescue errors before Sentry's middleware (which is not hard to do as the Sentry's middleware will be placed at the very front). and from a SDK's point of view, we can't possibly detect and resolve each of those cases from the SDK itself. so imo the best solution should be to have a standalone gem, like sentry-better_error for injecting the above patch.

but given that this is not a bug in SDK itself + we still have higher priority tasks, we don't plan to add the additional support at the moment. this is why it's marked as wontfix. but it'll also be kept open for people to look up the solution easier.

[sedubois]

OK. For info here is our initializer after updating from sentry-raven to sentry-ruby 4.1.1:

# https://github.com/getsentry/sentry-ruby/issues/738#issuecomment-750323266
if defined?(::BetterErrors::Middleware)
  module BetterErrorsSentryCompatibility
    def show_error_page(env, exception = nil)
      begin
        Sentry::Rack.capture_exception exception, env if exception
      rescue StandardError # rubocop:disable Lint/HandleExceptions
      end

      super
    end
  end

  Rails.application.config.after_initialize do
    if Sentry.configuration.rails.report_rescued_exceptions
      BetterErrors::Middleware.prepend BetterErrorsSentryCompatibility
    end
  end
end

[st0012]

@sedubois thanks for posting an updated version 👍

[st0012]

Good news: I came up with another way to address these kinds of issue in https://github.com/getsentry/sentry-ruby/pull/1168. The PR should fix this issue and will be included in version 4.1.2 of sentry-rails.

However, I won't backport this fix to the old sentry-raven SDK as this is not a critical issue. So I highly recommend you to migrate to the new SDK by following this guideline.

[cooperka]

With the latest sentry-rails v4.1.2, errors weren't being sent in development when I explicitly specified config.environment = "development".

This is the default (it uses RAILS_ENV) so I removed the config.environment line and it fixed the problem for me. Strange but happy it's working now.