these 2 derivations will be built:
  /nix/store/f3w8cyzgkxf0d1jpgcbmkzrkx2fl8ryq-iets-0.1.0.drv
  /nix/store/gf7gwpcb1p99javwzp7l8vrgqcc7zk92-iets-langtests.drv