Python/JavaScript dev env

shell.nix

{ pkgs ? import <nixpkgs> {} }:
let
  # yarn > 1.10.x
  unstable = import (fetchTarball {
    url = "https://releases.nixos.org/nixos/19.03/nixos-19.03.172138.5c52b25283a/nixexprs.tar.xz";
    sha256 = "14289382e88abeb2a049e948c301818a034bf09d306ce127d765a87ba644d205";
  }) {};
  app = pkgs.buildFHSUserEnv {
    name = "app";
    targetPkgs = pkgs: (with pkgs; [
      binutils
      gcc
      gnumake
      libffi.dev
      libjpeg.dev
      libxslt.dev
      nodejs
      openssl.dev
      python36Full
      sshpass
      unstable.yarn
      zlib
      zlib.dev
    ]) ++ (with pkgs.python36Packages; [
      pip
      virtualenv
    ]);
    profile = ''
      export SOURCE_DATE_EPOCH=$(date +%s)
    '';
    runScript = "bash";
  };
in app.env

./DEV_INSTALL script installs Python and JavaScript dependencies in the chrootenvironment.