Worked on improving dependency resolution error reporting in the luong-komorebi/cargo repository, focusing on enhancing reliability and developer experience. Refactored error message generation to use Registry::describe_source, enabling more accurate display of search locations when dependencies are missing. Expanded test coverage to include scenarios involving missing packages in source replacement directories, ensuring new error messages are validated and consistent across the codebase. This work reduced debugging time and support overhead by making error messages clearer and more actionable. Utilized Rust for implementation, applying skills in build systems, error handling, and test-driven development to deliver targeted, maintainable improvements.