Tokio: Tokio-async-await fails to compile on latest nightly

[tyrylu]

Version

Latest stable from crates.io, e. g. tokio-async-await 0.1.6, Tokio 0.1.18.

Platform

Latest rust nightly, e. g. rustc 1.35.0-nightly (3750348da 2019-04-08) on a x86_64 Windows 10, using latest msys2.

Subcrates

Definitely tokio-async-await

Description

When compiling a project which has tokio-async-await as a dependenci, its compilation fails with the following output:
`` Compiling serde_derive v1.0.90 Compiling pest_generator v2.1.0 Compiling devise_core v0.2.0 Compiling pear_codegen v0.1.2 Compiling diesel_derives v1.4.0 Compiling synstructure v0.10.1 Checking tokio-async-await v0.1.6 error[E0053]: methodpollhas an incompatible type for trait --> C:\Users\lukas\.cargo\registry\src\github.com-1ecc6299db9ec823\tokio-async-await-0.1.6\src\compat\forward.rs:56:5 | 56 | fn poll(mut self: Pin<&mut Self>, _waker: &Waker) -> StdPoll<Self::Output> { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability | = note: expected typefn(std::pin::Pin<&mut compat::forward::Compat>, &mut std::task::Context<'_>) -> std::task::Poll::Item, ::Error>> found typefn(std::pin::Pin<&mut compat::forward::Compat>, &std::task::Waker) -> std::task::Poll::Item, ::Error>>`

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\io\flush.rs:26:5
|
26 | fn poll(mut self: Pin<&mut Self>, _wx: &Waker) -> Poll {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut io::flush::Flush<'a, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::result::Result<(), std::io::Error>>
found type fn(std::pin::Pin<&mut io::flush::Flush<'a, T>>, &std::task::Waker) -> std::task::Poll<std::result::Result<(), std::io::Error>>

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\io\read.rs:28:5
|
28 | fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut io::read::Read<'a, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::result::Result<usize, std::io::Error>>
found type fn(std::pin::Pin<&mut io::read::Read<'a, T>>, &std::task::Waker) -> std::task::Poll<std::result::Result<usize, std::io::Error>>

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\io\read_exact.rs:33:5
|
33 | fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut io::read_exact::ReadExact<'a, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::result::Result<(), std::io::Error>>
found type fn(std::pin::Pin<&mut io::read_exact::ReadExact<'a, T>>, &std::task::Waker) -> std::task::Poll<std::result::Result<(), std::io::Error>>

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\io\write.rs:28:5
|
28 | fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut io::write::Write<'a, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::result::Result<usize, std::io::Error>>
found type fn(std::pin::Pin<&mut io::write::Write<'a, T>>, &std::task::Waker) -> std::task::Poll<std::result::Result<usize, std::io::Error>>

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\io\write_all.rs:33:5
|
33 | fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut io::write_all::WriteAll<'a, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::result::Result<(), std::io::Error>>
found type fn(std::pin::Pin<&mut io::write_all::WriteAll<'a, T>>, &std::task::Waker) -> std::task::Poll<std::result::Result<(), std::io::Error>>

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\sink\send.rs:30:5
|
30 | fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut sink::send::Send<'_, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::result::Result<(), <T as futures::Sink>::SinkError>>
found type fn(std::pin::Pin<&mut sink::send::Send<'_, T>>, &std::task::Waker) -> std::task::Poll<std::result::Result<(), <T as futures::Sink>::SinkError>>

error[E0053]: method poll has an incompatible type for trait
--> C:\Users\lukas.cargo\registry\src\github.com-1ecc6299db9ec823tokio-async-await-0.1.6\src\stream\next.rs:24:5
|
24 | fn poll(mut self: Pin<&mut Self>, _waker: &Waker) -> Poll {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability
|
= note: expected type fn(std::pin::Pin<&mut stream::next::Next<'a, T>>, &mut std::task::Context<'_>) -> std::task::Poll<std::option::Option<std::result::Result<<T as futures::Stream>::Item, <T as futures::Stream>::Error>>>
found type fn(std::pin::Pin<&mut stream::next::Next<'a, T>>, &std::task::Waker) -> std::task::Poll<std::option::Option<std::result::Result<<T as futures::Stream>::Item, <T as futures::Stream>::Error>>>

error: aborting due to 8 previous errors

For more information about this error, try rustc --explain E0053.
error: Could not compile tokio-async-await.
warning: build failed, waiting for other jobs to finish...
error: build failed
```

[taiki-e]

https://github.com/tokio-rs/tokio/pull/1041 will solve this.

However, futures_api will make several changes within the next few weeks, so probably it will take a while to release the next version.

Also, it can be avoided by pinning the nightly toolchain to the 2019-04-07 or early.

[tyrylu]

Thank you for the information.

[prasannavl]

@taiki-e - Is there any more changes to futures_api planned? O.o (unless I'm mistaken, that's pretty much it for now?)

Wondering if it makes sense to cut a release.. would be incredibly helpful to get the ball rolling on getting the ecosystem back up to speed with the latest nightly.

[emk]

If it helps anybody else, the most recent Rust which supports tokio, tokio-async-await, rls and clippy appears to be nightly-2019-03-23 as of April 22, 2019.

[qm3ster]

@emk or for those that do want latest nightly,

[dependencies]
futures-preview = "0.3.0-alpha.14"
tokio = { version = "0.1.18", features = ["async-await-preview"] }
[patch.crates-io]
tokio = { git = "https://github.com/tokio-rs/tokio" }
tokio-async-await = { git = "https://github.com/tokio-rs/tokio" }

currently works splendidly.

[tyrylu]

It works with nightly from 2019-04-07 for me.

[carllerche]

The nightly version that works with the async-await feature is tracked in the azure-pipelines.yml file.

The upcoming (#1053) release will support the latest nightly.

[carllerche]

A new crate has been published. Cheers!