What I'm seeing if I kick off a thread which news up a `tokio_core::reactor::Core` when our `Core` is constructed, schedules a no-op scheduled callback, and keep no references to the thread, is that my pants dies with SIGILL. Any idea why that would be?

--> does tokio have an expectation that

Core

always runs in the main thread and can handle signals? maybe https://github.com/rust-lang/rust/issues/21592 ?