Worked on the rust-lang/rust repository to improve the reliability of clippy-driver integration by addressing symbol resolution and environment variable handling. Focused on compiler development and tooling in Rust, the work involved updating RustcCallbacks::config to set config.extra_symbols, aligning its behavior with ClippyCallbacks::config. This change ensured that symbol resolution occurred correctly and prevented the leakage of random strings into symbol tables during builds. By resolving erroneous environment variable dependency records, the update stabilized dep-info generation and improved CI reliability. The approach emphasized reproducibility and maintainability, leveraging Rust and compiler tooling expertise to enhance build accuracy and standardize symbol handling.