these 2 derivations will be built:
  /nix/store/vzm1dzxm3ppxja0jgrzwrbfx3ycx98i7-hol-guard-3.3.0.drv
  /nix/store/yqwmd3s9flzzd7s88ka2jg90z0w8yjwy-check-hol-guard.drv