Install without Flakes

Recommended method: using `fetchFromGitHub`

The simplest way to use NixKraken without Flakes is to fetch it directly from GitHub inside home.nix.

{ lib, pkgs, ... }:

{
  imports = [
    # Import the NixKraken module from the fetched source (ie. "${fetcher}/module.nix")
    "${pkgs.fetchFromGitHub {
      owner = "nicolas-goudry";
      repo = "nixkraken";
      rev = "main";
      # rev = "<branch-name|commit-sha>";
      # tag = "<tag-name>"; # Use either `rev` or `tag`, not both!
      hash = lib.fakeHash; # Make sure to read the callout below
    }}/module.nix"
  ];
}

warning

About lib.fakeHash

A common pattern in Nix is to use a fake hash like lib.fakeHash or an empty string ("") as a placeholder.

When the configuration is built, the evaluation will fail. But the error message will output the expected hash, which can then be copied back into the configuration.

To get the hash without a failed evaluation, refer to the section on how to retrieve the release hash.

Alternative methods

If other fetchers or a dependency pinning tool should be used, see the options below.

Using other Nix fetchers

fetchzip

{ lib, pkgs, ... }:

{
  imports = [
    "${pkgs.fetchzip {
      url = "https://github.com/nicolas-goudry/nixkraken/archive/main.zip";
      # url = "https://github.com/nicolas-goudry/nixkraken/archive/<branch-name|commit-sha>.zip";
      # url = "https://github.com/nicolas-goudry/nixkraken/archive/refs/tags/<tag-name>.zip";
      hash = "<retrieved-hash>";
      # hash = lib.fakeHash;
    }}/module.nix"
  ];
}

fetchgit

{ lib, pkgs, ... }:

{
  imports = [
    "${pkgs.fetchgit {
      url = "https://github.com/nicolas-goudry/nixkraken.git";
      rev = "main";
      # rev = "<branch-name|commit-sha>";
      # tag = "<tag-name>"; # Use either `rev` or `tag`, not both!
      hash = "<retrieved-hash>";
      # hash = lib.fakeHash;
    }}/module.nix"
  ];
}

fetchTarball

{ lib, ... }:

{
  imports = [
    "${builtins.fetchTarball {
      url = "https://github.com/nicolas-goudry/nixkraken/archive/main.tar.gz";
      # url = "https://github.com/nicolas-goudry/nixkraken/archive/<branch-name|commit-sha>.tar.gz";
      # url = "https://github.com/nicolas-goudry/nixkraken/archive/refs/tags/<tag-name>.tar.gz";
      sha256 = "<retrieved-hash>";
      # sha256 = lib.fakeSha256;
    }}/module.nix"
  ];
}

Using pinning tools

niv

niv add nicolas-goudry/nixkraken

let
  sources = import ./nix/sources.nix;
in {
  imports = [
    sources.nixkraken + "/module.nix"
  ];
}

caution

These instructions are untested. Please report an issue if they are not working, or suggest a PR fixing them.

npins

npins add github nicolas-goudry nixkraken

let
  sources = import ./npins;
in {
  imports = [
    sources.nixkraken + "/module.nix"
  ];
}

caution

These instructions are untested. Please report an issue if they are not working, or suggest a PR fixing them.

Retrieve release hash

Users willing to avoid using lib.fakeHash can retrieve the release hash using either nix-prefetch-git or nix-prefetch-url, as shown below.

`nix-prefetch-git`

The command below outputs various information about NixKraken sources.

nix-prefetch-git --url git@github.com:nicolas-goudry/nixkraken.git --quiet

// Example response
{
  "url": "git@github.com:nicolas-goudry/nixkraken.git",
  "rev": "812365dfd82571d82751b192c90d3d6eca16d04c",
  "date": "2025-06-17T15:40:02+02:00",
  "path": "/nix/store/v42lgzcdygj8nyj193vrysi8il0aj8a5-nixkraken",
  "sha256": "1cpvfzdb7m16pj5ykj9dppyr1rm1gnzvhyb5qvvmg5ihbmqx6cgh",
  "hash": "sha256-8DHTcV0wllf3xmV5uL99oeaQ/b0tyemLvCbUs9p3+7I=",
  "fetchLFS": false,
  "fetchSubmodules": false,
  "deepClone": false,
  "leaveDotGit": false
}

Here, the relevant key is hash. Tools like jq can be used to extract it directly from the JSON output of the command:

nix-prefetch-git \
  --url git@github.com:nicolas-goudry/nixkraken.git \
  --quiet \
| jq -r '.hash'

💡 Tips

To retrieve the sources hash at a given point in history (tag or commit), use --rev <tag-name|commit-sha>.

To retrieve the sources hash for a given branch, use --rev refs/heads/<branch-name>.

The following commands use nix-prefetch-url to get the Nix base32 hash from the unpacked sources archive retrieved from GitHub. The hash is then handed to nix-hash (or nix hash convert, which requires the nix-command experimental feature to be enabled) to get the final hash expected by fetchers.

nix-hash \
  --to-sri \
  --type sha256 \
  "$(nix-prefetch-url \
       --unpack "https://github.com/nicolas-goudry/nixkraken/archive/main.tar.gz")"

# ...or using new nix commands
nix hash convert \
  --hash-algo sha256 \
  --from nix32 \
  "$(nix-prefetch-url \
       --unpack "https://github.com/nicolas-goudry/nixkraken/archive/main.tar.gz")"

💡 Tips

To retrieve the sources hash at a given tag, replace main.tar.gz by refs/tags/<tag-name>.tar.gz.

To retrieve the sources hash at a given point in history (branch or commit), replace main.tar.gz by <branch-name|commit-sha>.tar.gz.

NixKraken docs