these 3 derivations will be built:
  /nix/store/93rhf0q5xvbknjc9qjf1k3ziidq2a12a-hol_guard-3.6.0.tar.gz.drv
  /nix/store/k1rx3pf6rn5pdx413rcaan9327r7vpar-hol-guard-3.6.0.drv
  /nix/store/g6dp4prinhwj66c9x5n3cm9rr6smnbkd-check-hol-guard.drv