Dave Anderson

Thanks for the report @DanielJoyce - we'll investigate. To confirm, you explicitly enabled AutoInstruments via config setting, correct?

Can you check to see if it's being enabled in your environment variables? It would be `SCOUT_AUTO_INSTRUMENTS=true`

Hrm, this wouldn't turn on the AutoInstruments feature. This is just [attaching pieces of data](https://docs.scoutapm.com/#ruby-custom-context) to the detailed traces we collect. > It looks like we turn it on programmatically....

Can you let me know what version of `parser` and `ast` is in your `Gemfile.lock`? I can't reproduce with `parser =2.5.0.3` and `ast = 2.4.0` as [seen in this gist](https://gist.github.com/dlanderson/12f65ca1de210abc71a1caf3d7e57e90)....

I ran through versions of `parser` and it looks like a bug was introduced in `2.7.0.0`. Can you pin your `parser` version to `2.6.4.1`? In `Gemfile`: ``` gem 'parser', '=...

@DanielJoyce I'd recommend just leaving AutoInstruments turned off until we can reconcile the behavior of parser >= 2.7.0.0. Just unset `SCOUT_AUTO_INSTRUMENTS` env var and restart your app servers. AutoInstruments is...

Thanks for the report @jeffblake - I'm surprised that we would interfere with ActionCable connections, since we don't have any instrumentation there. Can you provide some info on which rails...

Thanks @danmayer - I'm not familiar with how Coverband detects which code has been executed. Can you give me a pointer to how it works? Does coverband work when https://github.com/Shopify/bootsnap...

The [Scoutprof extension](https://github.com/scoutapp/scout_apm_ruby/blob/scoutprof/ext/stacks/extconf.rb) has code that allows us to fall back in case we cannot compile. I think we could use the same approach here.

Thanks for the report @alexottoboni. Do you happen to be running your apps in containers or have any resource limits applied via cgroups?