these 2 derivations will be built:
  /nix/store/0ba3d7m3l0aq40whirvr6v3waiqvafva-iets-0.1.0.drv
  /nix/store/x0x74mfpmh4h1kzf1jgzrn5yg1yx9p4x-iets-langtests.drv