Solana: Proc-macro (<2) support with rust analyzer 0.3.220 or later

68750c1f The Solana community is constantly looking for ways to improve the development experience, and a significant update to the VSCode Rust Analyzer extension has recently been made. The latest version 0.3.220 or later has removed support for proc macro versions `<2`, which are a critical dependency for many Solana projects. Proc macros allow developers to extend the functionality of their code at compile time, making it easier to write efficient and maintainable code. However, they require specific compiler features that were not available in older versions of Rust, such as `<2`. As of December 16, 2024, the new version of the Solana Rust Analyzer extension no longer supports proc macro versions `<2`. This means that users who are using Solana 1.18.17 or earlier in their projects may experience issues when trying to compile with the latest analyzer.

What this means for developers

To avoid compatibility issues, it is recommended to update your project dependencies to ≥ 0.3.220 or later. This update includes several important changes that improve performance and stability:

Improved support for newer Rust features: The new parser now correctly uses the Proc_macro function in Solana 1.18.17, allowing for better integration with proc macros.

Better error messages: The updated parser provides more informative error messages to help developers diagnose issues.

New test cases: The developer has added new test cases to ensure that the parser handles various scenarios correctly.

Upgrading your project

If you are using Solana 1.18.17 or earlier, you must upgrade your project to ≥ 0.3.220 or later. You can do this by:

Install the latest version of the VSCode Rust Analyzer extension from the [official repository] (

Update the Cargo.toml file to ensure it is compatible with the new analyzer.

Run the “cargo build” and check for errors or warnings.

After completing these steps, you will be able to take advantage of the latest Solana Rust analysis features and improvements. Happy coding!