these 2 derivations will be built:
  /nix/store/ignbqnmdhd9d2s68m4958plkv6ignlw3-nixos-test-driver-pgrouting.drv
  /nix/store/m6mwa4f852h5xya5bbz87dpvixjyzvh0-vm-test-run-pgrouting.drv