Prometheus.InvalidMetricArityError after phoenix Update

[David Schilling]

I updated phoenix to Version 1.6.
After that i get the following error in the log:

[error] Handler "telemetry_web__event_handler" has failed and has been detached. Class=:error
Reason=%Prometheus.InvalidMetricArityError{expected: 2, present: 3}
Stacktrace=[
  {:prometheus_metric, :check_mf_exists, 4,
   [file: 'src/prometheus_metric.erl', line: 149]},
  {:prometheus_histogram, :insert_placeholders, 3,
   [file: 'src/metrics/prometheus_histogram.erl', line: 443]},
  {:prometheus_histogram, :insert_metric, 5,
   [file: 'src/metrics/prometheus_histogram.erl', line: 431]},
  {:prometheus_histogram, :observe, 4,
   [file: 'src/metrics/prometheus_histogram.erl', line: 203]},
  {Prometheus.Metric.Histogram, :observe, 2,
   [file: 'lib/prometheus/metric/histogram.ex', line: 101]},
  {:telemetry, :"-execute/3-fun-0-", 4,
   [
     file: '/Users/david/projects/private/BetterTyping/deps/telemetry/src/telemetry.erl',
     line: 150
   ]},
  {:lists, :foreach, 2, [file: 'lists.erl', line: 1342]},
  {Plug.Telemetry, :"-call/2-fun-0-", 4,
   [file: 'lib/plug/telemetry.ex', line: 76]},
  {Enum, :"-reduce/3-lists^foldl/2-0-", 3, [file: 'lib/enum.ex', line: 2396]},
  {Plug.Conn, :run_before_send, 2, [file: 'lib/plug/conn.ex', line: 1690]},
  {Plug.Conn, :send_resp, 1, [file: 'lib/plug/conn.ex', line: 399]},
  {TyperacerWeb.LobbyController, :action, 2,
   [file: 'lib/typeracer_web/controllers/lobby_controller.ex', line: 1]},
  {TyperacerWeb.LobbyController, :phoenix_controller_pipeline, 2,
   [file: 'lib/typeracer_web/controllers/lobby_controller.ex', line: 1]},
  {Phoenix.Router, :__call__, 2, [file: 'lib/phoenix/router.ex', line: 355]},
  {TyperacerWeb.Endpoint, :plug_builder_call, 2,
   [file: 'lib/typeracer_web/endpoint.ex', line: 1]},
  {TyperacerWeb.Endpoint, :"call (overridable 3)", 2,
   [file: 'lib/plug/debugger.ex', line: 136]},
  {TyperacerWeb.Endpoint, :call, 2,
   [file: 'lib/typeracer_web/endpoint.ex', line: 1]},
  {Phoenix.Endpoint.Cowboy2Handler, :init, 4,
   [file: 'lib/phoenix/endpoint/cowboy2_handler.ex', line: 54]},
  {:cowboy_handler, :execute, 2,
   [
     file: '/Users/david/projects/private/BetterTyping/deps/cowboy/src/cowboy_handler.erl',
     line: 37
   ]},
  {:cowboy_stream_h, :execute, 3,
   [
     file: '/Users/david/projects/private/BetterTyping/deps/cowboy/src/cowboy_stream_h.erl',
     line: 306
   ]}
]

This is how i configure it:

application.ex:

...
 Typeracer.PhoenixInstrumenter.setup()
    Typeracer.PipelineInstrumenter.setup()
    Typeracer.RepoInstrumenter.setup()
    Prometheus.Registry.register_collector(:prometheus_process_collector)
    Typeracer.PrometheusExporter.setup()

    :ok =
      :telemetry.attach(
        "prometheus-ecto",
        [:typeracer, :repo, :query],
        &Typeracer.RepoInstrumenter.handle_event/4,
        %{}
      )

    PrometheusPhx.setup()
...