Worked on the Saghen/nixpkgs repository to enhance the trunk-io package by introducing a mainProgram attribute within the package.nix definition. This update focused on improving package metadata, enabling more accurate tooling auto-discovery and facilitating downstream automation without altering build or runtime behavior. The approach centered on maintainability and correctness, ensuring that the new metadata was non-breaking and did not impact existing workflows. Utilized Nix and package management expertise to implement this feature, emphasizing clarity in package structure. No bugs were addressed during this period, as the work remained strictly within the scope of metadata improvements and package definition refinement.