`io_close(descriptor)` is the one true interface

[samuel-williams-shopify]

While io_close(io) was an internal development step only, it was never published in an official release, so you should not need this compatibility indirection.

carbon_fiber/lib/carbon_fiber/async.rb

Line 149 in 2b9420f

fd = io.respond_to?(:fileno) ? io.fileno : io.to_i

[yaroslav]

@samuel-williams-shopify thank you! Missed your issue
Seems to be fixed in #4