In May 2025, H2H contributed to the facebook/buck2-prelude repository by delivering a targeted fix to the C++ build system, focusing on toolchain override reliability. Using Starlark and leveraging expertise in build system configuration and C++ toolchain management, H2H updated the cxx_toolchain_override logic to correctly honor user-specified dwp and llvm_link executables. This adjustment addressed issues where overridden toolchains were not reliably selected, leading to improved build stability and reproducibility across different development environments. By reducing build failures and shortening debugging cycles for toolchain changes, H2H’s work enhanced the robustness of the Buck2-prelude C++ build infrastructure.