these 2 derivations will be built:
  /nix/store/dnls1p7hfzw3nvf71y20vpfl271a1b17-nixos-test-driver-postgis.drv
  /nix/store/qffbpfz7dv4h8j0vchb185z20jq3axd9-vm-test-run-postgis.drv