Rust Devblog 261 May 2026

Better error messages for your macro users.

if n.is_multiple_of(7) ...

Temporarily building an older crate that declares rust-version = "1.80" while you’re on 1.75 . rust devblog 261

#!/usr/bin/env cargo-script //! ```cargo //! [dependencies] //! regex = "1.10" //! anyhow = "1.0" //! ``` use regex::Regex; use anyhow::Result; Better error messages for your macro users

If you use #![deny(clippy::pedantic)] or custom lints, they are now more predictable. TokenStream let diag = Diagnostic::new(Severity::Error

// In your proc macro #[proc_macro] pub fn my_macro(input: TokenStream) -> TokenStream let diag = Diagnostic::new(Severity::Error, "This usage is invalid") .help("Try using `foo` instead of `bar`") .emit(); // ...

cargo script script.rs Add #!/usr/bin/env cargo-script shebang and chmod +x for executable scripts. 4. Standard library: integer::is_multiple_of What’s new: New method is_multiple_of on integer types.