airbrake: Airbrake 500 Errors

Our app (right now) is basically idle. It’s getting tickled by a status/liveness check at api/health but that’s it.

Despite this fact, we see this error showing up:

**Airbrake: unexpected code (500). Body: {"code":500,"type":"Internal Server Error","message":"An error occurred while processing your request...

In the context of the log line:

I, [2022-05-19T15:41:12.023541 airbrake/airbrake-ruby#1]  INFO -- : [56d40f40-b0ef-4699-a8bc-317fc7f308e1] Completed 200 OK in 0ms (Views: 0.1ms | ActiveRecord: 0.0ms | Allocations: 78)
I, [2022-05-19T15:41:12.554973 airbrake/airbrake-ruby#1]  INFO -- : [54b5e972-8da5-49d0-89fc-aaae132f7442] Started GET "/api/health" for 10.1.133.213 at 2022-05-19 15:41:12 +0000
I, [2022-05-19T15:41:12.557242 airbrake/airbrake-ruby#1]  INFO -- : [54b5e972-8da5-49d0-89fc-aaae132f7442] Processing by HealthController#index as HTML
I, [2022-05-19T15:41:12.559390 airbrake/airbrake-ruby#1]  INFO -- : [54b5e972-8da5-49d0-89fc-aaae132f7442] Completed 200 OK in 1ms (Views: 0.1ms | ActiveRecord: 0.0ms | Allocations: 78)
E, [2022-05-19T15:41:13.487472 airbrake/airbrake-ruby#1] ERROR -- : **Airbrake: unexpected code (500). Body: {"code":500,"type":"Internal Server Error","message":"An error occurred while processing your request...
E, [2022-05-19T15:41:19.270981 airbrake/airbrake-ruby#1] ERROR -- : **Airbrake: unexpected code (500). Body: {"code":500,"type":"Internal Server Error","message":"An error occurred while processing your request...
E, [2022-05-19T15:41:23.173085 airbrake/airbrake-ruby#1] ERROR -- : **Airbrake: unexpected code (500). Body: {"code":500,"type":"Internal Server Error","message":"An error occurred while processing your request...
E, [2022-05-19T15:41:23.431794 airbrake/airbrake-ruby#1] ERROR -- : **Airbrake: unexpected code (500). Body: {"code":500,"type":"Internal Server Error","message":"An error occurred while processing your request...

At the same time, we have eliminated this path from the Performance Monitor:

Airbrake.add_performance_filter do |resource|
  resource.ignore! if resource.route =~ %r{/api/health}
end

At the time we first ran into this we guessed that the performance stuff was choking for some reason. I can’t think of what else might cause this issue?

We are running:

ruby on rails with latest gem ruby 3.1.0 ‘rails’, ‘~> 7.0.2.4’