these 2 derivations will be built:
  /nix/store/k491nbmik2ki7bz6qh8cilbg5k7z8qc1-nixos-test-driver-postgis.drv
  /nix/store/bkv2zvkycwi0n6cnrvg4k3id6dzsjds4-vm-test-run-postgis.drv