Building

Build Commands

Command Purpose

nix build .#nixosConfigurations.<host>.config.system.build.toplevel

Build a host's NixOS system

nix build .#homeConfigurations.<user>@<host>.activationPackage

Build a Home-Manager activation

nix fmt

Format code and check syntax

nix flake check

Evaluate all configurations and run linters

nix flake show

Display available outputs

nix develop

Open development shell

nix develop --command true

Test that devShell can be entered

DevEnv Requirement

This repository uses devenv for devShells and checks. You must provide the devenv-root input override for nix flake check and nix develop :

nix flake check --override-input devenv-root "file+file://$PWD/.devenv/root"

nix develop --override-input devenv-root "file+file://$PWD/.devenv/root"

Common Build Patterns

Build a specific host

Build nixdev server

nix build .#nixosConfigurations.nixdev.config.system.build.toplevel

Build nixmi desktop

nix build .#nixosConfigurations.nixmi.config.system.build.toplevel

Build a user's home configuration

Build racci's config on nixmi

nix build .#homeConfigurations."racci@nixmi".activationPackage

Evaluate without building

Check if configuration evaluates

nix eval .#nixosConfigurations.nixdev.config.system.build.toplevel --apply 'x: "ok"'

Get a specific option value

nix eval .#nixosConfigurations.nixdev.config.networking.hostName

Format specific files

Format changed files

nix fmt path/to/file.nix

Format multiple files

nix fmt modules/nixos/services/*.nix

Troubleshooting Builds

If a build fails:

• Check the error message for the failing derivation

• Try nix log <drv> to see build logs

• Use --show-trace for evaluation errors: nix build .#... --show-trace

• For infinite recursion, check for circular imports or option definitions