these 2 derivations will be built:
  /nix/store/lcr4za8vzk0xzz5f5ydaskfjpdqq0qhw-pdfvision-0.16.0.drv
  /nix/store/nw67lb1d0c3j50c0bkhf3hkhqy9b899p-check-pdfvision.drv