>Go, Rust, and Zig make it impossible to interrupt most blocking syscalls, because they automatically retry on EINTR.

This is not true of Rust. Some of the convenience wrappers (std::io::Read::read_exact, etc) on top of the basic primitives (std::io::Read::read, etc) do retry for you (and explicitly document it), but not "Rust" as a whole. The primitives map one-to-one to calls of read/write/sendto/recvfrom and bubble up ErrorKind::Interrupted to the caller just fine.