Setup magisk environment & toolchain in NixOS

magisk-env.nix

{
  pkgs ? import <nixpkgs> {},
  unstable ? import (fetchTarball https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz) {},
  buildFHSUserEnv ? opt: (unstable.buildFHSUserEnv opt).env,
}:

buildFHSUserEnv rec {
  name = "magisk-env";

  targetPkgs = p: (with pkgs;
    [
      python3
      openjdk11-bootstrap
      zlib
      gcc
      android-studio
    ]
  );

  # This setting assume that you are using the default path of sdk.
  # Change this if you specify the path to somewhere else.
  profile = "export ANDROID_SDK_ROOT=$HOME/Android/Sdk";

  runScript = "bash";
}