{
  config,
  pkgs,
  lib,
  ...
}: {
  nix.settings.trusted-public-keys = [
    # "hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs="
  ];
  nix.settings.substituters = [
    "https://cache.nixos.org"
    # "https://hydra.nixos.org"
  ];
  nix.settings.trusted-substituters = [
    "https://cache.nixos.org"
    # "https://hydra.nixos.org"
  ];

  nix.daemonCPUSchedPolicy = "idle";
  nix.daemonIOSchedClass = "idle";
  nix.settings.max-jobs = lib.mkDefault "auto";
  nix.settings.cores = lib.mkDefault 0;
  nix.settings.sandbox = true;

  environment.etc."lvm/lvm.conf".text = ''
    devices {
      issue_discards = 1
    }
  '';

  environment.variables = {NIX_PATH = lib.mkForce pkgs.nixPath;};

  # Fonts, I18N, Date ...
  fonts.fonts = [pkgs.corefonts];

  console.font = "lat9w-16";

  i18n = {defaultLocale = "en_US.UTF-8";};
  time.timeZone = "Etc/UTC";
  services.gpm.enable = true;

  services.packagekit.enable = true;
  services.openssh.enable = true;
  networking.firewall.enable = true;

  # Activation scripts for impure set up of paths in /
  system.activationScripts.bin = ''
    echo "setting up /bin..."
    mkdir -p /bin
    ln -sfT ${pkgs.bash}/bin/bash /bin/.bash
    mv -Tf /bin/.bash /bin/bash
  '';

  # TODO: find out if this workaround is still required from nixos 20.03 onwards
  # system.activationScripts.etcX11sessinos = ''
  #   echo "setting up /etc/X11/sessions..."
  #   mkdir -p /etc/X11
  #   ln -sfT ${config.services.xserver.displayManager.session.desktops} /etc/X11/.sessions
  #   mv -Tf /etc/X11/.sessions /etc/X11/sessions
  # '';

  system.activationScripts.lib64 = ''
    echo "setting up /lib64..."
    mkdir -p /lib64
    ln -sfT ${pkgs.glibc}/lib/ld-linux-x86-64.so.2 /lib64/.ld-linux-x86-64.so.2
    mv -Tf /lib64/.ld-linux-x86-64.so.2 /lib64/ld-linux-x86-64.so.2
  '';

  programs.zsh.enable = true;
  users.defaultUserShell = pkgs.zsh;
  environment.pathsToLink = ["/share/zsh"];
  programs.fuse.userAllowOther = true;
}