tra.txt

IO::Async::Private::Scheduler#new originating fiber creating io_fiber, 
  Thread.current #<Thread:0xc08 id=8 pid=3996597 source=/Users/cremes/dev/mygit/ruby-io/c/test_async_sockets.rb:9 status=run>, 
  Fiber.current #<Fiber:0xc0c thread_name=ruby.8 fiber_id=0 status=run>

IO::Async::Private::Scheduler#io_fiber running loop, 
  Thread.current #<Thread:0xc08 id=8 pid=3996597 source=/Users/cremes/dev/mygit/ruby-io/c/test_async_sockets.rb:9 status=run>, 
  Fiber.current #<IO::Internal::Fiber:0xc10 thread_name=ruby.8 fiber_id=9 status=transfer source=/Users/cremes/dev/mygit/ruby-io/lib/io/async/private/scheduler.rb:15>, 
  calling fiber #<Fiber:0xc0c thread_name=ruby.8 fiber_id=0 status=run>

IO::Async::Private::Scheduler#io_fiber_loop transferring to originating_fiber, 
  Thread.current #<Thread:0xc08 id=8 pid=3996597 source=/Users/cremes/dev/mygit/ruby-io/c/test_async_sockets.rb:9 status=run>, 
  Fiber.current #<IO::Internal::Fiber:0xc10 thread_name=ruby.8 fiber_id=9 status=transfer source=/Users/cremes/dev/mygit/ruby-io/lib/io/async/private/scheduler.rb:15>, 
  originating_fiber #<Fiber:0xc0c thread_name=ruby.8 fiber_id=0 status=run>

I think there's a bug in Rubinius. See above on lines 11-13. We are on thread id 8 and Fiber.current id 9 trying to transfer
to originating fiber id 0. Note that "originating fiber" has ruby.8 as its creating thread (that's what thread_name is for,
right?). My guess is that the thread "hosting" the fiber and Thread.current are getting crossed up somehow.

Exception in thread: attempt to transfer fiber across threads: current thread: 8, Fiber Thread: 1 (FiberError)
Exception: attempt to transfer fiber across threads: current thread: 8, Fiber Thread: 1 (FiberError)
Exception: `FiberError' /Users/cremes/dev/mygit/ruby-io/lib/io/async/private/scheduler.rb:18 - attempt to transfer fiber across threads: current thread: 8, Fiber Thread: 1
                call # Proc at core/proc.rb:20
   { } in initialize # IO::Async::Private::Scheduler at /Users/cremes/dev/mygit/ruby-io/lib/io/async/private/scheduler.rb:18
       io_fiber_loop # IO::Async::Private::Scheduler at /Users/cremes/dev/mygit/ruby-io/lib/io/async/private/scheduler.rb:53

attempt to transfer fiber across threads: current thread: 8, Fiber Thread: 1 (FiberError)