these 2 derivations will be built:
  /nix/store/lmwrf1vlgawr1y0gq3l2i6hvhwjdapd6-iets-0.1.0.drv
  /nix/store/g3gxbnxdq7nm0b0lggn3y5h6f7bgshyh-iets-diff-e2e.drv