---

name: nix description: | Nix commands and package management guide. Use when:

• Running nix build, nix run
• Adding custom packages
• Using nurl for hash acquisition

---

Nix Skill

1. nix build

• YOU MUST: Always use --no-link option with nix build

  Copynix build .#rumdl --no-link
  

• IMPORTANT: Without --no-link, a ./result symlink is created

2. nix run

• IMPORTANT: Packages registered in packages can be run with nix run

  Copynix run .#pike -- scan -d ./terraform
  

3. Adding Custom Packages

• YOU MUST: See CONTRIBUTING.md section 1.4.2 for adding new custom packages
• IMPORTANT: Hash acquisition flow
  1. Get hash using nurl: nurl https://github.com/<owner>/<repo> <tag>
  2. Get vendorHash/cargoHash via build error (got: line)
• IMPORTANT: Add doCheck = false; if tests fail

4. nurl

• IMPORTANT: nurl generates Nix fetcher calls from repository URLs

  Copynurl https://github.com/rvben/rumdl v0.0.206
  

• IMPORTANT: Output can be used directly in fetchFromGitHub

  CopyfetchFromGitHub {
    owner = "rvben";
    repo = "rumdl";
    rev = "v0.0.206";
    hash = "sha256-XXX...";
  }
  

• IMPORTANT: For cargoHash/vendorHash, use build error method (nurl does not support these)