let
  nixpkgs = import .lib/nix/nixpkgs.nix;
  pkgs = import nixpkgs {
    config   = {}; # Make the config pure, ignoring user's config.
    overlays = []; # Make the overlays pure, ignoring user's overlays.
  };
in
pkgs.stdenv.mkDerivation {
  name = "commonsoft-nix";
  src = null;
  buildInputs = [
    # Nix
    nixpkgs

    # Development
    pkgs.direnv
    pkgs.git
    pkgs.less
    pkgs.man
    pkgs.tig
    pkgs.vim
    #pkgs.tmux
    #pkgs.rxvt_unicode.terminfo

    # Building
    pkgs.coreutils
    pkgs.gnumake
    #pkgs.binutils

    # Adminsys
    pkgs.cryptsetup
    pkgs.libfaketime
    pkgs.nixops
    pkgs.time
    pkgs.curl
    (pkgs.glibcLocales.override {
      allLocales = false;
      locales = [
        "en_US.UTF-8/UTF-8"
        "fr_FR.UTF-8/UTF-8"
      ];
    })
    pkgs.gnupg
    pkgs.pass
    #pkgs.sqlite
    pkgs.htop
    pkgs.ncurses
    pkgs.ncdu
    #pkgs.virtualbox
    pkgs.sqlite
    pkgs.procps
    pkgs.sudo # NOTE: sudo needs to be own by root with the setuid bit,
              # but this won't be the case for the sudo provided by Nix outside NixOS,
              # hence the addition of $PATH_FHS in shellHook
              # to provide the host system's sudo.
              # WARNING: beware that sudo may reset the environment,
              # and especially PATH, to some system's default.
    pkgs.tree
    pkgs.utillinux
    pkgs.which
    pkgs.xdg_utils
    #pkgs.openssl
    #pkgs.inetutils
    #pkgs.mailutils
    #pkgs.dnsutils
  ];
  #enableParallelBuilding = true;
  shellHook = ''
    export NIX_PATH="nixpkgs=${nixpkgs}:nixpkgs-commonsoft=$PWD/lib/nixpkgs-commonsoft"
    #NIX_PATH+=":nixpkgs-overlays="$PWD"/install/overlays.nix"
    #NIX_PATH+=""

    # executables
    PATH_NIX=$(dirname $(readlink ~/.nix-profile/bin/nix))
    PATH_NIXOS=/run/wrappers/bin
    PATH_NIX_BUILD="$PWD"/result/bin
    PATH_FHS="$PWD"/.lib/nix/fhs-bin
    PATH_FHS_VBOX="$PWD"/.lib/fhs-vbox-bin
    export PATH="$PATH_NIX_BUILD:$PWD/bin:$PATH_NIXOS:$PATH_FHS_VBOX:$PATH_FHS:$PATH:$PATH_NIX"

    # locales
    export LANG=fr_FR.UTF-8
    export LC_CTYPE=fr_FR.UTF-8

    # gpg
    gpgconf --launch gpg-agent
    export SSH_AUTH_SOCK=$(gpgconf --list-dirs agent-ssh-socket)
    export GPG_TTY=$(tty)
    export GNUPGHOME="$PWD"/../sec/gnupg
    install -dm700 "$GNUPGHOME"

    # password-store
    export PASSWORD_STORE_DIR="$PWD"/../sec/pass

    # git
    ln -fnsr \
     "$PWD"/.lib/git/hooks/prepare-commit-msg--longuest-common-prefix \
     "$PWD"/.git/hooks/prepare-commit-msg

    # nixops
    export NIXOPS_DEPLOYMENT="virtualbox"
    export NIXOPS_STATE="$PWD"/.var/nixops/state.nixops
    # Extend the Nix interpreter
    # to enable builtins.extraBuiltins,
    # which provides an unsafe exec useful to get secrets
    # from the local password-store.
    NIXOPS_OPTS+=" --show-trace"
    NIXOPS_OPTS+=" --option plugin-files $PWD/result/nix/plugins/libnix-extra-builtins.so"
    NIXOPS_OPTS+=" --option extra-builtins-file $PWD/result/nix/extra-builtins.nix"
    export NIXOPS_OPTS

    # disnix
    #export DISNIXOS_USE_NIXOPS=1
    #export DISNIX_CLIENT_INTERFACE=disnix-nixops-client
    #export DISNIX_PROFILE=default
    #export DISNIX_TARGET_PROPERTY=hostname
    #export DYSNOMIA_STATEDIR=var/dysnomia
  '';
}