aarch64-darwin bombon-transformer compliation failure

[vetsin]

cargoBuildHook flags: -j 12 --target aarch64-apple-darwin --offline --profile release
...
       >    Compiling bombon-transformer v0.4.0 (/private/tmp/nix-build-bombon-transformer-0.4.0.drv-0/source)
       > error[E0658]: `let` expressions in this position are unstable
       >    --> src/cyclonedx.rs:181:12
       >     |
       > 181 |         if let Some(src) = derivation.src
       >     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       >     |
       >     = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information
       >
       > For more information about this error, try `rustc --explain E0658`.
       > error: could not compile `bombon-transformer` (bin "bombon-transformer") due to 1 previous error
       For full logs, run 'nix log /nix/store/5zwlvjcji0s3m7jxyh8y4sbi6lga26cv-bombon-transformer-0.4.0.drv'

when it's following github:NixOS/nixpkgs/nixos-25.05

[nikstur]

You need to use nixos-unstable or wait until nixos-25.11 is available because bombon needs at least rustc 1.88 which was released in June 2025 (after the last stable release).

According to the Nixpkgs tracking issue 25.11 will be released at the end of November.