Failed to compile on Mac OS

[jqmichael]

Added dependency on rio on MacOS 10.14.6.

[dependencies]
rio = "0.9.4"

With cargo 1.47.0, cargo check failed with the error message below:

   Compiling libc v0.2.80
    Checking rio v0.9.4
error[E0432]: unresolved imports `super::io_uring`, `super::Uring`
  --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/completion.rs:11:5
   |
11 |     io_uring::io_uring_cqe, FromCqe, Measure, Uring, M,
   |     ^^^^^^^^                                  ^^^^^ no `Uring` in the root
   |     |
   |     maybe a missing crate `io_uring`?

error[E0433]: failed to resolve: use of undeclared type or module `Config`
   --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/lib.rs:219:5
    |
219 |     Config::default().start()
    |     ^^^^^^ use of undeclared type or module `Config`

error[E0433]: failed to resolve: use of undeclared type or module `io_uring`
   --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/lib.rs:298:22
    |
298 |     fn from_cqe(cqe: io_uring::io_uring_cqe) -> Self;
    |                      ^^^^^^^^ use of undeclared type or module `io_uring`

error[E0433]: failed to resolve: use of undeclared type or module `io_uring`
   --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/lib.rs:302:22
    |
302 |     fn from_cqe(cqe: io_uring::io_uring_cqe) -> usize {
    |                      ^^^^^^^^ use of undeclared type or module `io_uring`

error[E0433]: failed to resolve: use of undeclared type or module `io_uring`
   --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/lib.rs:309:20
    |
309 |     fn from_cqe(_: io_uring::io_uring_cqe) {}
    |                    ^^^^^^^^ use of undeclared type or module `io_uring`

error[E0412]: cannot find type `Rio` in this scope
   --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/lib.rs:218:28
    |
218 | pub fn new() -> io::Result<Rio> {
    |           -                ^^^ not found in this scope
    |           |
    |           help: you might be missing a type parameter: `<Rio>`

error[E0282]: type annotations needed
  --> /Users/juqing/.cargo/registry/src/github.com-1ecc6299db9ec823/rio-0.9.4/src/completion.rs:25:19
   |
25 |             item: None,
   |                   ^^^^ cannot infer type for type parameter `T` declared on the enum `Option`

error: aborting due to 7 previous errors

[tekjar]

@jqmichael iouring is linux specific

[jqmichael]

Thanks @tekjar. I can totally understand if it failed to run at run time. But I'm a little surprised it failed to compile.

Was there a Rust feature that I can tweak to make it compile on Mac?