Worked on the NixOS/nixpkgs repository to enhance build reliability and package stability, focusing on compatibility with evolving toolchains. Addressed a build failure in qgnomeplatform by updating the build system configuration in Nix, explicitly enforcing a minimum CMake policy version to ensure successful builds with CMake 4. Upgraded the pyfa package to a newer release, updating the source hash to maintain reproducibility and downstream compatibility. Applied skills in build system configuration and package management, leveraging the Nix language to deliver targeted fixes. The work emphasized maintaining reproducible builds and supporting ongoing compatibility as the ecosystem evolves with new toolchain versions.