[ribelo]

Go's approach to async programming is indeed simpler, but its FFI and handling of stateful coroutines can introduce complexity and overhead when bridging with external code. Using CGO is slow because it requires synchronization of the coroutine state between libc and Go. Everyone avoids CGO whenever possible, so it is not a solution.

Rust chose a different path that is not more complex, but the complexity lies elsewhere.

[yencabulator]

Just an extra bit of clarity: the relative slowness of CGo calls is a conscious trade-off that enables Go threads to be much lighter weight. It's not an inherent aspect of the design, but a trade-off you pay for wanting more lightweight green threads. Choosing to not follow the age old C ABI internally means you have to bridge that gap if and when you come to it.