tokio::task::block_in_place can only be called inside spawned tasks

[Marwes]

The following panics

#[test]
fn block_on_from_block_on() {
    let mut rt = runtime::Runtime::new().unwrap();
    rt.block_on_std(async {
        tokio_02::task::block_in_place(move || ());
    });
}

Easy workaround by wrapping the bblock_in_place call with a tokio::spawn, but it had me confused for a bit.

[hawkw]

Yeah, this is a Tokio 0.2 limitation — there is an upstream ticket about it: tokio-rs/tokio#1838. As per tokio-rs/tokio#1838 (comment), this limitation may be removed in the future.