To reproduce
> rustc -vV
rustc 1.75.0 (82e1608df 2023-12-21)
binary: rustc
commit-hash: 82e1608dfa6e0b5569232559e3d385fea5a93112
commit-date: 2023-12-21
host: aarch64-apple-darwin
release: 1.75.0
LLVM version: 17.0.6
> cargo new --lib thiserr-test
> cargo add thiserror
# make sure version is 1.0.53
> cargo build
error[E0554]: `#![feature]` may not be used on the stable release channel
--> /Users/muradb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/thiserror-1.0.53/src/lib.rs:238:50
|
238 | #![cfg_attr(error_generic_member_access, feature(error_generic_member_access))]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Change version to =1.0.52.
Now cargo build works fine.
I checked that the CI for 1.0.53 has ran fine yesterday, so this might be an issue with OS (unlikely tho)?