error[E0658]: use of unstable library feature 'matches_macro'

[jaredforth]

I am getting the following error when trying to compile a crate that depends on actix-utils:

error[E0658]: use of unstable library feature 'matches_macro'
  --> /home/jared/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-utils-2.0.0/src/timeout.rs:61:38
   |
61 |             TimeoutError::Timeout => matches!(other, TimeoutError::Timeout),
   |                                      ^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/65721

error: aborting due to previous error

The error in question was closed in October of 2019, but the compiler is complaining about line 61 in timeout.rs.

I am on Ubuntu on WSL(Windows Subsystem for Linux), and have the following versions of Rust tooling:

• rustup 1.21.1
• rustc 1.41.1
• cargo 1.41.0

My rustup toolchain is: stable-x86_64-unknown-linux-gnu (default).

I have the following Actix related dependencies in the project:

actix = { version="0.9.0", features=["http"] }
actix-multipart = "0.2.0"
actix-web = "2.0.0"
actix-rt = "1.0.0"
async-std = "1.4.0"
actix-cors = "0.2.0"
actix-web-httpauth = "0.4.1"

What could be causing this issue? I have successfully compiled this project within the last month and have never seen this problem before.

[robjtede]

Running cargo tree -i actix-utils:2.0.0 will show the dependency path though I suspect it's coming from actix-server v1.0.4.

All actix crates have a minimum supported version of rust v1.42 now, which is when the matches macro was stabilized.

To remedy this, either pin to actix-server = "=1.0.3" or update to rust v1.42.

[jaredforth]

@robjtede Thanks!

I updated to v1.46 and it's working now.