Tokio: Tokio 0.2.4 not playing well with latest stable version of Rust

[seguidor777]

Rust 1.39.0 (latest stable)

Crates:

tokio 0.2.4
futures 0.3.1

Platform

Linux latitude 4.19.0-kali5-amd64 #1 SMP Debian 4.19.37-6kali1 (2019-07-22) x86_64 GNU/Linux

Description

I created a project using the proxy example
After running cargo build I see the following errors:

   Compiling proxy v0.1.0 (/home/seguidor777/Rust/proxy)
error[E0432]: unresolved imports `tokio::net::TcpListener`, `tokio::net::TcpStream`
  --> src/main.rs:26:18
   |
26 | use tokio::net::{TcpListener, TcpStream};
   |                  ^^^^^^^^^^^  ^^^^^^^^^ no `TcpStream` in `net`
   |                  |
   |                  no `TcpListener` in `net`

error[E0433]: failed to resolve: could not find `main` in `tokio`
  --> src/main.rs:33:10
   |
33 | #[tokio::main]
   |          ^^^^ could not find `main` in `tokio`

error[E0425]: cannot find function `spawn` in crate `tokio`
  --> src/main.rs:50:16
   |
50 |         tokio::spawn(transfer);
   |                ^^^^^ not found in `tokio`
help: possible candidate is found in another module, you can import it into scope
   |
25 | use std::thread::spawn;
   |

error[E0425]: cannot find function `copy` in module `io`
  --> src/main.rs:62:32
   |
62 |     let client_to_server = io::copy(&mut ri, &mut wo);
   |                                ^^^^ not found in `io`
help: possible candidates are found in other modules, you can import them into scope
   |
25 | use core::intrinsics::copy;
   |
25 | use core::ptr::copy;
   |
25 | use futures::core_reexport::intrinsics::copy;
   |
25 | use futures::core_reexport::ptr::copy;
   |
and 5 other candidates

error[E0425]: cannot find function `copy` in module `io`
  --> src/main.rs:63:32
   |
63 |     let server_to_client = io::copy(&mut ro, &mut wi);
   |                                ^^^^ not found in `io`
help: possible candidates are found in other modules, you can import them into scope
   |
25 | use core::intrinsics::copy;
   |
25 | use core::ptr::copy;
   |
25 | use futures::core_reexport::intrinsics::copy;
   |
25 | use futures::core_reexport::ptr::copy;
   |
and 5 other candidates

error[E0277]: `main` has invalid return type `impl core::future::future::Future`
  --> src/main.rs:34:20
   |
34 | async fn main() -> Result<(), Box<dyn Error>> {
   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^ `main` can only return types that implement `std::process::Termination`
   |
   = help: consider using `()`, or a `Result`

error: aborting due to 6 previous errors

Some errors have detailed explanations: E0277, E0425, E0432, E0433.
For more information about an error, try `rustc --explain E0277`.
error: could not compile `proxy`.

To learn more, run the command again with --verbose.

Could you please let me know if there really is a problem with the versions or if there are others that I should use?

[asonix]

it looks to me like you haven't added any features to your tokio dependency.

try

tokio = { version = "0.2.4", features = ["full"] }

It also looks like Result<(), Box<dyn Error>> doesn't implement Termination, which is unfortunate. You could try replacing Box<dyn Error> with anyhow::Error (docs) and see if that gets you where you need.

[seguidor777]

You are absolutely right, I am new to Rust and did not know of the features addition.

Thanks a lot!