The Nim compiler, a builder function, and some packaged libraries are available in Nixpkgs. Until now each compiler release has been effectively backwards compatible so only the latest version is available.

Nim program packages in Nixpkgs

Nim programs can be built using nimPackages.buildNimPackage. In the case of packages not containing exported library code the attribute nimBinOnly should be set to true.

The following example shows a Nim program that depends only on Nim libraries:

{ lib, nimPackages, fetchFromGitHub }:

nimPackages.buildNimPackage (finalAttrs: {
  pname = "ttop";
  version = "1.0.1";
  nimBinOnly = true;

  src = fetchFromGitHub {
    owner = "inv2004";
    repo = "ttop";
    rev = "v${finalAttrs.version}";
    hash = "sha256-x4Uczksh6p3XX/IMrOFtBxIleVHdAPX9e8n32VAUTC4=";

  buildInputs = with nimPackages; [ asciigraph illwill parsetoml zippy ];


Nim library packages in Nixpkgs

Nim libraries can also be built using nimPackages.buildNimPackage, but often the product of a fetcher is sufficient to satisfy a dependency. The fetchgit, fetchFromGitHub, and fetchNimble functions yield an output that can be discovered during the configurePhase of buildNimPackage.

Nim library packages are listed in pkgs/top-level/nim-packages.nix and implemented at pkgs/development/nim-packages.

The following example shows a Nim library that propagates a dependency on a non-Nim package:

{ lib, buildNimPackage, fetchNimble, SDL2 }:

buildNimPackage (finalAttrs: {
  pname = "sdl2";
  version = "2.0.4";
  src = fetchNimble {
    inherit (finalAttrs) pname version;
    hash = "sha256-Vtcj8goI4zZPQs2TbFoBFlcR5UqDtOldaXSH/+/xULk=";
  propagatedBuildInputs = [ SDL2 ];

buildNimPackage parameters

All parameters from stdenv.mkDerivation function are still supported. The following are specific to buildNimPackage:

  • nimBinOnly ? false: If true then build only the programs listed in the Nimble file in the packages sources.

  • nimbleFile: Specify the Nimble file location of the package being built rather than discover the file at build-time.

  • nimRelease ? true: Build the package in release mode.

  • nimDefines ? []: A list of Nim defines. Key-value tuples are not supported.

  • nimFlags ? []: A list of command line arguments to pass to the Nim compiler. Use this to specify defines with arguments in the form of -d:${name}=${value}.

  • nimDoc ? false`: Build and install HTML documentation.

  • buildInputs ? []: The packages listed here will be searched for *.nimble files which are used to populate the Nim library path. Otherwise the standard behavior is in effect.