non-exhaustive patterns

[aurexav]

With rust nightly-2020-05-21:

error[E0004]: non-exhaustive patterns: `Done(_)` not covered
   --> /home/travis/.cargo/git/checkouts/substrate-a7fa553ead635512/7e9a2ae/client/offchain/src/api/http.rs:183:10
    |
183 |             match when_ready {
    |                   ^^^^^^^^^^ pattern `Done(_)` not covered
    | 
   ::: /home/travis/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.5/src/future/maybe_done.rs:18:5
    |
18  |     Done(Fut::Output),
    |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
    = note: the matched value is of type `futures_util::future::maybe_done::MaybeDone<futures_util::future::poll_fn::PollFn<[closure@/home/travis/.cargo/git/checkouts/substrate-a7fa553ead635512/7e9a2ae/client/offchain/src/api/http.rs:181:60: 181:86 sender:&mut &mut hyper::body::body::Sender]>>`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0004`.
error: could not compile `sc-offchain`.
To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed
The command ".maintain/ci/build_script.sh" exited with 101.

[gui1117]

could we expect rustc to recover from this regression ? Done is covered by:

				future::MaybeDone::Done(Ok(())) => {}
				future::MaybeDone::Done(Err(_)) => return Err(HttpError::IoError),

[burdges]

It could be related to, or even a simpler case of, rust-lang/rust#71977 You could ask if rustc wants a pull request for a test that covers these.

[bkchr]

Rustc bug: rust-lang/rust#72476