This broke some internal events tests, like GC events, so I'll take a look soon.

Thanks for picking up this fix!

Also, I want to make it so that there's a flag to TracePoint#enable to make them global.

This would be great as well! I work on the profiler included in the ddtrace gem and while we don't have support for gathering information from non-main Ractors yet, it would be great if there was a global mechanism to say "I want to get informed of things, regardless of where they come from".

This way, we won't have to do things like intercept Ractor creation to make sure we reactivate our tracepoints for every new one that gets created.

Even if such an API is only available from C (I understand it may be harder to get Ruby-level tracepoints working cross-ractor), it would be incredibly valuable :)

Thanks for picking up this fix!

Not a problem 😄

I think a :global keyword being introduced for TracePoint#enable would be good. It doesn't look too complicated to get global tracepoint hooks to work alongside ractor hooks, but I'll leave that work for a separate commit and after (or if) this gets accepted.

Just wanted to follow up to ask if there's any plans to finish this. This would help enable reliable memory allocation profiling in our infrastructure.

This should be getting more attention soon. I plan on working on the 'debug' gem to enable breakpoints to work inside Ractors, and this PR would enable that work.