Using nix package manager in Debian

The nix package manager is available in Debian since May 2020. Why would one use it in Debian?

• learn about nix
• install software that might not be available in Debian
• install software without root access
• declare software necessary for a user’s environment inside $HOME/.config

Especially the last point nagged me every time I set up a new Debian installation. My emacs configuration and my Desktop setup expects certain software to be installed.

Please be aware that I’m a beginner with nix and that my config might not follow best practice. Additionally many nix users are already using the new flakes feature of nix that I’m still learning about.

So I’ve got this file at .config/nixpkgs/config.nix¹:

with (import <nixpkgs> {});
{
  packageOverrides = pkgs: with pkgs; {
    thk-emacsWithPackages = (pkgs.emacsPackagesFor emacs-gtk).emacsWithPackages (
      epkgs:
      (with epkgs.elpaPackages; [
        ace-window
        company
        org
        use-package
      ]) ++ (with epkgs.melpaPackages; [
        editorconfig
        flycheck
        haskell-mode
        magit
        nix-mode
        paredit
        rainbow-delimiters
        treemacs
        visual-fill-column
        yasnippet-snippets
      ]) ++ [    # From main packages set
      ]
    );

    userPackages = buildEnv {
      extraOutputsToInstall = [ "doc" "info" "man" ];
      name = "user-packages";
      paths = [
        ghc
        git
        (pkgs.haskell-language-server.override { supportedGhcVersions = [ "94" ]; })
        nix
        stack
        thk-emacsWithPackages
        tmux
        vcsh
        virtiofsd
      ];
    };
  };
}

Every time I change the file or want to receive updates, I do:

nix-env --install --attr nixpkgs.userPackages --remove-all

You can see that I install nix with nix. This gives me a newer version than the one available in Debian stable. However, the nix-daemon still runs as the older binary from Debian. My dirty hack is to put this override in /etc/systemd/system/nix-daemon.service.d/override.conf:

[Service]
ExecStart=
ExecStart=@/home/thk/.local/state/nix/profile/bin/nix-daemon nix-daemon --daemon

I’m not too interested in a cleaner way since I hope to fully migrate to Nix anyways.