ScoutApm.Command does not work in Elixir 1.14

[pvthuyen]

Implementations for ScoutApm.Command are not recognized by Elixir 1.14. I've included the stack trace and errors below. I'm guessing that it's because we are defining the implementation inside the modules.

** (Protocol.UndefinedError) protocol ScoutApm.Command not implemented for %ScoutApm.Command.Batch{commands: [%ScoutApm.Command.StartRequest{timestamp: ~N[2022-10-12 04:05:26.620713], request_id: "Abv3nnKNCVMm"}, %ScoutApm.Command.StartSpan{timestamp: ~N[2022-10-12 04:05:26.620713], request_id: "Abv3nnKNCVMm", span_id: "rNE42VNUmsI5", parent: nil, operation: "Job/WallChannel.check_access"}, %ScoutApm.Command.StopSpan{timestamp: ~N[2022-10-12 04:05:26.800598], request_id: "Abv3nnKNCVMm", span_id: "rNE42VNUmsI5"}, %ScoutApm.Command.FinishRequest{timestamp: ~N[2022-10-12 04:05:26.800598], request_id: "Abv3nnKNCVMm"}]} of type ScoutApm.Command.Batch (a struct). This protocol is implemented for the following type(s): Kernel
    (scout_apm 1.0.7) lib/scout_apm/commands.ex:1: ScoutApm.Command.impl_for!/1
    (scout_apm 1.0.7) lib/scout_apm/commands.ex:2: ScoutApm.Command.message/1
    (scout_apm 1.0.7) lib/scout_apm/tracked_request.ex:227: anonymous fn/1 in ScoutApm.TrackedRequest.build_collector_fn/1
    (scout_apm 1.0.7) lib/scout_apm/tracked_request.ex:110: ScoutApm.TrackedRequest.stop_layer/2
    (scout_apm 1.0.7) lib/scout_apm/tracked_request.ex:259: ScoutApm.TrackedRequest.with_saved_tracked_request/1

[dlanderson]

Thanks @pvthuyen. @jeregrine is this something RokkinCat can help with?

[pvthuyen]

I tried to fix the issue and upgrade Elixir version to 1.14 in this PR. Please give it a review.

https://github.com/scoutapp/scout_apm_elixir/pull/124

[jeregrine]

Sorry for delay. I will take alook now.

[jeregrine]

@pvthuyen I need to do some more testing but master branch should be fully functioning now thanks to your PR and some extra stuff I needed to do.

Please confirm by pointing your mix dep to github {:scout_apm, github: "scoutapp/scout_apm_elixir"} and running it.

[pvthuyen]

Thanks @jeregrine. I will try it on my project later. I have a small comment on your commit though, https://github.com/scoutapp/scout_apm_elixir/commit/4b9c43fb03131e827faf80709851fa96ac2a74b3#r87762936.

[pvthuyen]

I'm getting this when running my project after updating the dependencies.

** (Mix) Could not start application scout_apm: exited in: ScoutApm.Application.start(:normal, [])
    ** (EXIT) an exception was raised:
        ** (MatchError) no match of right hand side value: {:error, {:shutdown, {:failed_to_start_child, ScoutApm.Core.AgentManager, {:EXIT, {:undef, [{ScoutApm.Core.AgentManager, :start_link, [[]], []}, {:supervisor, :do_start_child_i, 3, [file: 'supervisor.erl', line: 414]}, {:supervisor, :do_start_child, 2, [file: 'supervisor.erl', line: 400]}, {:supervisor, :"-start_children/2-fun-0-", 3, [file: 'supervisor.erl', line: 384]}, {:supervisor, :children_map, 4, [file: 'supervisor.erl', line: 1242]}, {:supervisor, :init_children, 2, [file: 'supervisor.erl', line: 350]}, {:gen_server, :init_it, 2, [file: 'gen_server.erl', line: 423]}, {:gen_server, :init_it, 6, [file: 'gen_server.erl', line: 390]}]}}}}}
            (scout_apm 1.0.7) lib/scout_apm/application.ex:20: ScoutApm.Application.start/2
            (kernel 8.1.2) application_master.erl:293: :application_master.start_it_old/4

[pvthuyen]

It's due to ScoutApm.Core.AgentManager does not have the correct start_link definition. Sent a PR for it.

https://github.com/scoutapp/scout_apm_elixir/pull/125

[pvthuyen]

@jeregrine master branch seems to work on my project now. Please kindly help me release a new version.