these 2 derivations will be built:
  /nix/store/zz2kkwwqbcxvqapqvp8ajah4mf04ykm2-iets-0.1.0.drv
  /nix/store/0k9b00s1rnvak46p1p5zfrwdpxjk2zbw-iets-langtests.drv