Scout Agent Running in Console in Rails 7

[mabrikan]

We faced an issue in which scout agent will start and worker thread will get initialized when running bundle exec rails console.

I inspected the code that does the checks and I believe that method interactive? in lib/scout_apm/environment.rb is the one doing so

    # If both stdin & stdout are interactive and the Rails::Console constant is defined
    def interactive?
      defined?(::Rails::Console) && $stdout.isatty && $stdin.isatty
    end

I did some debugging and discovered that in later versions of rails (6 or higher) where spring is used to load the app, ::Rails::Console can become undefined. Of course this causes the method above to return false, hence the agent gets initialized.

I searched for a fix and stumbled upon this thread in another project, but discussing the same issue.

A workaround is to disable spring using export DISABLE_SPRING=true before running rails console

I just wanted to share this info, also maybe if there is a way to detect if spring is working and add a condition to the method above.

Version info:
ruby '3.2.1'
'rails', '~> 7.0.4.3'
'scout_apm', ''5.3.5'

[jrothrock]

Hey @mabrikan,

I'm having a hard time recreating this unfortunately:

❯ bundle exec spring rails console
Running via Spring preloader in process 15085
Loading development environment (Rails 7.1.3)
 :001 > defined?(::Rails::Console)
 => "constant" 

I tried both spring v.4.0.0 and v4.1.3, as well as Rails 6.0.x.

I take it that bouncing spring didn't help at all?