What problem does it solve? Managing a multi-host NixOS flake repository involves repetitive, error-prone tasks: deciding where new modules belong, keeping host-specific settings separate from shared modules, formatting and evaluating Nix code, and recovering from eval or build failures such as fixed-output hash mismatches. This Skill encodes the repository's conventions so every change follows the same validated workflow. ## Core Features & Use Cases - Module and package management: Add user applications as modules/home/<name>.nix files, system services under modules/nixos, and host-only settings under hosts/<host>/, with auto-import conventions respected. - Validation workflow: Run nixfmt, git diff --check, and targeted nix eval commands for the Home Manager activation package or system toplevel of each affected host before applying anything. - Failure handling: Diagnose fixed-output hash mismatches, untracked-file flake path errors, and silent script failures with structured recovery steps. - Script resolution: Use the bundled resolve-nix-script helper to locate the correct sns_until, nix_update, or nix_clean script for the current host, falling back to shared defaults. - Use Case: You want to install a new application on your laptop only. The Skill creates modules/home/drawio.nix, stages the file so Nix can see it, evaluates both hosts' Home Manager packages, and stops short of applying unless you ask. ## Quick Start Use the spreadconfig-nix skill to add a new Home Manager package for my current host and validate the change without switching the system.
