Worked on improving the Ghostunnel package in the hmemcpy/nixpkgs repository by addressing a critical build compatibility issue on macOS. The solution involved adding missing build inputs and adjusting test flags, ensuring that Ghostunnel now compiles and passes tests reliably on Darwin systems. This change reduced platform-specific build failures and streamlined the release process for macOS, benefiting downstream deployments. The work demonstrated a strong command of Nix for build system configuration and cross-platform development, with careful attention to the nuances of the Darwin toolchain and continuous integration workflows. The update enhanced CI reliability and improved macOS release readiness for the package.