these 2 derivations will be built:
  /nix/store/jccw7p7ig5i5dqfg3agqmkgr5qyv3q05-iets-0.1.0.drv
  /nix/store/p37pdhg7fqigl7klkgn58p026dld7bm8-iets-diff-e2e.drv