these 2 derivations will be built:
  /nix/store/rmg2lkzffxhnxgm03r8sgni1qm3msms6-hol-guard-3.6.3.drv
  /nix/store/9c4g7cc2kbs5zrdb5cv34zv56k1jgv1d-check-hol-guard.drv