Issue Description

Summary

We are experiencing a transient NoMethodError: undefined method 'rails' for nil in production. The error comes through with an empty backtrace and request UUIDs don't seem to show up in Sentry or our cloud logging. The error typically happens once per path then disappears on subsequent requests, suggesting an issue with the initialization.

Versions:

• sentry-rails 5.24.0
• sentry-ruby 5.24.0
• Rails 8.0.2
• Ruby 3.4.4

Related Issue

Similar issue #2386 - same error in rescued_exception_interceptor.rb:20 accessing Sentry.configuration.rails without checking initialization. Closed, but pattern might still exist elsewhere.

Investigation

Sentry::Rails::CaptureExceptions#capture_exception (line 30) accesses Sentry.configuration.rails without checking initialization:

return if show_exceptions?(exception, env) && !Sentry.configuration.rails.report_rescued_exceptions

Since Sentry.configuration returns nil when not initialized (sentry-ruby/lib/sentry-ruby.rb:168-171), calling .rails on nil would raise this error. The initialize method checks Sentry.initialized? first, but capture_exception does not.

Related Code

• sentry-rails/lib/sentry/rails/capture_exceptions.rb:30
• sentry-ruby/lib/sentry-ruby.rb:168-171 (configuration method)

Reproduction Steps

Hard to reproduce, as there is no error context that gives us good clues about where to home in.

Expected Behavior

No error

Actual Behavior

We see a very cryptic error without any context

Ruby Version

3.4.4

SDK Version

5.24.0

Integration and Its Version

Rails 8.0.2

Sentry Config

# typed: false

Sentry.init do |config|
  config.dsn = "https://..."
  config.breadcrumbs_logger = [:active_support_logger, :http_logger]

  # Set the environment
  config.environment = Rails.env
  config.enabled_environments = %w[production]

  # Release tracking
  config.release = ENV["HEROKU_SLUG_COMMIT"] || ENV["GIT_COMMIT"] || `git rev-parse HEAD`.chomp

  # Configure which exceptions should not be reported
  config.excluded_exceptions += [
    "ActionController::RoutingError",
    "ActiveRecord::RecordNotFound",
    "Sidekiq::SoftRetry"
  ]

  # Filter sensitive data
  config.before_send = lambda do |event, hint|
    # Filter out sensitive parameters
    event.request&.data&.delete(:password)
    event.request&.data&.delete(:password_confirmation)
    event
  end

  config.traces_sample_rate = 0.2
  config.profiles_sample_rate = 1.0
end