these 2 derivations will be built:
  /nix/store/pzkk408k48dpikjs9nz2gm1f1yg57xa8-iets-0.1.0.drv
  /nix/store/ixpr8rs8hpib1qhgvw7czvbzhisxw3z5-iets-diff-e2e.drv