It's not async by default. It's concurrent. In order to get async, you have to do a ton of wrapping, e.g. https://github.com/elixir-lang/elixir/blob/v1.9.4/lib/elixir...

...which also a Rust port does exist for Haiku at least after a quick search. [0]

[0] https://depot.haiku-os.org/#!/pkg/rust_bin/haikuports/1/36/0...

I know. I'm not sure I understand.