these 2 derivations will be built:
  /nix/store/pxiy5cyvbwym6q5q8c39hgxivah42p6a-ZCode-3.9.1-linux-x64.deb.drv
  /nix/store/fs6077imfr9h2yv50pglhkyfyb80qzhq-zcode-3.9.1.drv