Dependency Tracing

Dependency tracing in Nix allows you to understand the relationships between packages in your system configuration.

Forward Path Tracing

This section answers the question: "What are the dependencies of an installed package?"

Print a store path's dependency tree with:

nix-store --query --tree /nix/store/...

Get a package's store path with:

Replace YOUR_CONFIG with the name of your NixOS or Home Manager configuration, and PACKAGE with the name of the package you want to analyze.

NixOS

nix path-info ~/.config/nixos#nixosConfigurations.YOUR_CONFIG.pkgs.PACKAGE

Home Manager

nix path-info ~/.config/nixos#homeConfigurations.YOUR_CONFIG.pkgs.PACKAGE

Backward Path Tracing

This section answers the question: "What are parents of an installed package?" or "Why is a certain package installed?"

Print a package's dependency path with:

Replace YOUR_CONFIG with the name of your NixOS or Home Manager configuration, and PACKAGE with the name of the package you want to analyze.

NixOS

nix why-depends --derivation ~/.config/nixos#nixosConfigurations.YOUR_CONFIG.config.system.build.toplevel ~/.config/nixos#nixosConfigurations.YOUR_CONFIG.pkgs.PACKAGE

Home Manager

nix why-depends --derivation ~/.config/nixos#homeConfigurations.YOUR_CONFIG.activationPackage ~/.config/nixos#homeConfigurations.YOUR_CONFIG.pkgs.PACKAGE