these 2 derivations will be built:
  /nix/store/wy81i1rw2k498lrms87by4nb5b9j2map-hol-guard-3.18.0.drv
  /nix/store/p4q7b81944kz1c5jwwxnxm1gqby8w8pi-check-hol-guard.drv