error[E0658]: impl Trait in associated types is unstable

[codeBearll]

Hi, I find a error when I run "cargo +nightly build --release", log is like this:

error[E0658]: impl Trait in associated types is unstable
--> /home/czx/.cargo/registry/src/mirrors.ustc.edu.cn-61ef6e0cd06fb9b8/monoio-0.0.9/src/io/async_read_rent.rs:60:30
|
60 | type ReadFuture<'a, B> = impl std::future::Future<Output = crate::BufResult<usize, B>> where
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #63063 rust-lang/rust#63063 for more information
= help: add #![feature(impl_trait_in_assoc_type)] to the crate attributes to enable

error[E0658]: impl Trait in associated types is unstable
--> /home/czx/.cargo/registry/src/mirrors.ustc.edu.cn-61ef6e0cd06fb9b8/monoio-0.0.9/src/io/async_read_rent.rs:62:31
|
62 | type ReadvFuture<'a, B> = impl std::future::Future<Output = crate::BufResult<usize, B>> where
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #63063 rust-lang/rust#63063 for more information
= help: add #![feature(impl_trait_in_assoc_type)] to the crate attributes to enable

.........................................

I have set rustup as "rustup override set nightly"
info: using existing install for 'nightly-x86_64-unknown-linux-gnu'
info: override toolchain for '/home/czx/code/monoio-benchmark' set to 'nightly-x86_64-unknown-linux-gnu'

nightly-x86_64-unknown-linux-gnu unchanged - rustc 1.73.0-nightly (32303b219 2023-07-29)

So what might be the problem?