Nixpkgs/Contributing

Development in NixOS primarily driven by the work in nixpkgs on GitHub. This repository contains both all packages available in your NixOS channel and all the options you can use for configuring your system with your configuration.nix. To get your text editor to recognize Nix expressions, consider installing a Nix Editor Modes for Nix Files.

Report issues

Any issue can be reported in the nixpkgs issue tracker on GitHub. Keep in mind that all work on nixpkgs is being done by volunteers and you cannot expect a quick response and solution for all problems you may face. In general Pull Requests have a much shorter round-trip-time.

Create pull requests

If you want to see your package being provided by a channel, creating an issue will most likely not enough. It is up to you to create a nix package description in Nixpkgs and create a pull request in the Nixpkgs repository. Pull requests are a way to tell a GitHub project that you've created some changes, which maintainers can easily review, comment on and, and finally merge into the repository.

See How to create pull requests in nixpkgs CONTRIBUTING.md.

Hack Nixpkgs

Make any modifications you want to your local copy of the repository, then build the package from the root of the nixpkgs directory with:

nix-build -A $yourpackage

The output of your build will be located under the result/ subdirectory. Try running the freshly built binaries in result/bin and check that everything is OK.

To test the changes on a NixOS machine, rebuild the system using your newly hacked Nixpkgs by executing:

sudo nixos-rebuild switch -I nixpkgs=/path/to/local/nixpkgs

Run tests locally

Pushing commits to Github will run tests on Github.
We can run these tests locally, to reduce "commit noise" from failing tests

cd nixpkgs

# Basic evaluation checks
nix-build pkgs/top-level/release.nix -A tarball.nixpkgs-basic-release-checks \
--arg supportedSystems '[ "aarch64-darwin" "aarch64-linux" "x86_64-linux" "x86_64-darwin"  ]'

# list all derivations
nix-env --query --available --out-path --file ./. --show-trace

# build
nix-build -A $yourpackage

Tests on Github:

• Basic evaluation checks
• Checking EditorConfig
  • Read https://editorconfig.org/#download to configure your editor
• ofborg-eval will call nix-build -A $yourpackage

Called without required argument

This error is produced by nixpkgs-basic-release-checks (Basic evaluation checks)

anonymous function at /path/to/your-package.nix called without required argument 'some-dependency'

Usually, a dependency (some-dependency) is not available on a certain platform, for example on aarch64-darwin

To see how other packages handle this dependency:

cd nixpkgs/pkgs
grep -r some-dependency
# -r = --recursive

Avoid alias

Solution 1: Replace alias names with the real package names. For example:

• utillinux → util-linux
• double_conversion → double-conversion

Make optional

Solution 2: Make it an optional dependency:

{ lib
, stdenv
, some-dependency ? null
, another-dependency
}:

stdenv.mkDerivation {
  buildInputs =
    [ another-dependency ]
    ++ lib.optionals (!stdenv.isDarwin) [ some-dependency ]
    # some-dependency is missing on darwin
  ;
}

Manage your local repository

Tips & tricks for managing your nixpkgs checkout are kept in the page on git.

Becoming a Nixpkgs maintainer

See maintainers in nixpkgs

Building all of the packages you maintain

nix-build maintainers/scripts/build.nix --argstr maintainer your-nick

Maintain your nixpkgs fork

Update master

Add nixpkgs as a remote called upstream:

git remote add upstream https://github.com/NixOS/nixpkgs.git

You only have to do it once.

git checkout master        #1
git fetch upstream
git branch -u upstream/master

1. make sure you're on the master branch

after the above steps you only have to git pull to update the master branch

source