Nix User Repository (NUR)

You can extend your NUR repository to include reusable Nix logic:

• Overlays: Use the overlays attribute. Each overlay should be a valid Nix overlay (e.g., self: super: { ... }).
• Library functions: Use the lib attribute to provide reusable functions for users.

Example default.nix for overlays and lib:

{ pkgs }: {
  overlays = {
    my-overlay = import ./my-overlay;
  };
  lib = {
    myFunc = x: x + 1;
  };
}

{ pkgs }: 
with pkgs.lib; 
{
  lib = {
    hexint = x: hexvals.${toLower x};
    hexvals = listToAttrs (imap (i: c: { name = c; value = i - 1; }) (stringToCharacters "0123456789abcdef"));
  };
}

Using Flakes

If you are using Flakes, you can access Home Manager modules directly from the NUR input.

# In your Home Manager configuration
{
  imports = lib.attrValues nur.repos.moredhel.modules.homeManager;

  services.unison = {
    enable = true;
    profiles = {
      org = {
        src = "/home/moredhel/org";
        dest = "/home/moredhel/org.backup";
        extraArgs = "-batch -watch -ui text -repeat 60 -fat";
      };
    };
  };
}

Without Flakes

If you are not using Flakes, you must manually import the NUR repository using fetchTarball to access the modules.

let
  nur-no-pkgs = import (builtins.fetchTarball "https://github.com/nix-community/NUR/archive/main.tar.gz") {};
in
{
  imports = lib.attrValues nur-no-pkgs.repos.moredhel.homeModules;
}

To use NUR in a Flake-based setup, add it to your inputs. You should use inputs.nixpkgs.follows = "nixpkgs"; to ensure NUR uses the same Nixpkgs instance as your project. Once included, you can access NUR via its overlay (nur.overlays.default) or through legacyPackages.<system>.

Note: When using Flakes, you can access NUR modules directly in your NixOS configuration or Home Manager imports.

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    nur = {
      url = "github:nix-community/NUR";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };
};

Once NUR is installed, packages are accessed via the nur.repos.<contributor>.<package> namespace.

Warning: NUR packages are community-contributed and are not reviewed by Nixpkgs members. It is recommended to check expressions before installing them.

Common usage patterns:

Using nix-shell:

$ nix-shell -p nur.repos.mic92.hello-nur

Using nix-env:

$ nix-env -f '<nixpkgs>' -iA nur.repos.mic92.hello-nur

In NixOS configuration.nix:

# configuration.nix
environment.systemPackages = with pkgs; [
  nur.repos.mic92.hello-nur
];

NUR typically checks for repository updates once a day via GitHub Actions. To force an update immediately after pushing changes to your repository, use the NUR update service via a POST request.

Command:

curl -XPOST https://nur-update.nix-community.org/update?repo=<your-repo-name>

curl -XPOST https://nur-update.nix-community.org/update?repo=mic92

To host packages on NUR, create a repository containing a default.nix at the top level. The repository must return a set of Nix derivations and take a pkgs argument.

Important Rules:

• Do not use with import <nixpkgs> {};. Instead, use the provided pkgs argument for all dependencies.
• Each package should be a directory containing its own default.nix.
• Use pkgs.callPackage to compose your package set.
• For development, you can provide a default value for pkgs (e.g., pkgs ? import <nixpkgs> {}).

Example Repository Structure (default.nix):

{ pkgs ? import <nixpkgs> {} }:
{
  hello-nur = pkgs.callPackage ./hello-nur {};
}

{ pkgs }: 
{
  hello-nur = pkgs.callPackage ./hello-nur {};
}

NUR provides modules that can be imported directly into your NixOS configuration. You can use the default NUR overlay or import specific contributor modules.

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    nur = {
      url = "github:nix-community/NUR";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { self, nixpkgs, nur }: {
    nixosConfigurations.myConfig = nixpkgs.lib.nixosSystem {
      # ...
      modules = [
        # Adds the NUR overlay
        nur.modules.nixos.default
        # NUR modules can be imported directly:
        nur.repos.iopq.modules.nixos.xraya
        # Or via legacyPackages (legacy path):
        # nur.legacyPackages."${system}".repos.iopq.modules.xraya
      ];
    };
  };
}

Using builtins.fetchTarball without a sha256 only caches the download for 1 hour. To ensure reproducible builds and avoid constant internet access, pin NUR to a specific commit by providing a URL to the archive and its corresponding sha256 hash.

1. Choose a version from NUR Commits.
2. Get the hash by running nix-prefetch-url --unpack <url> on the archive URL.

builtins.fetchTarball {
  url = "https://github.com/nix-community/NUR/archive/3a6a6f4da737da41e27922ce2cfacf68a109ebce.tar.gz";
  sha256 = "04387gzgl8y555b3lkz9aiw9xsldfg4zmzp930m62qw8zbrvrshd";
}

To add a single package from NUR to a devShell in a flake.nix, include NUR in your inputs and apply its overlay to your pkgs instance.

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    nur = {
      url = "github:nix-community/NUR";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { self, nixpkgs, flake-utils, nur }: 
    flake-utils.lib.eachDefaultSystem (system: 
      let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [ nur.overlays.default ];
        };
      in
      {
        devShells.default = pkgs.mkShell {
          packages = [ pkgs.nur.repos.mic92.hello-nur ];
        };
      }
    );
}