these 2 derivations will be built:
  /nix/store/lbffgavpfyg2paqj7dq137359n68f7za-hol-guard-3.8.1.drv
  /nix/store/j10xj3b43hwfm6xk0zw6cn1786g2bx1s-check-hol-guard.drv