{
  pkgs ? import <nixpkgs> {},
  src
}:
let
  # patched contains path to store of this command's out
  # use patched
  patched = pkgs.runCommand "test0" {
    src = src;
  } ''
    mkdir $out;
    echo ${pkgs.lib.strings.concatStringsSep ":" src}
    date > $out/bla
  '';
in
  pkgs.runCommand "test1" {
    src2 = patched;
  } ''
    echo "step 2!!"
    mkdir $out;
    echo "src2 is $src2"

    echo ${patched}
  ''