Seb Meyer enhanced the build-time reliability of the EmilHvitfeldt/xgboost R package by focusing on cross-platform compatibility and robust error handling. He implemented targeted C++ and Shell-based checks for backtrace and fopen64, ensuring smoother installation across Windows, macOS, and Linux. Seb conditionally defined DMLC-related macros based on detected functions and refined endianness detection logic to improve runtime consistency. By updating Makevars.in to propagate new definitions, he addressed platform-specific build issues and stabilized the package’s compilation process. This work demonstrated depth in build system configuration and cross-platform development, directly reducing install-time failures and improving the developer and end-user experience.