these 2 derivations will be built:
  /nix/store/n49dymabcacnapbjs7sapm4rd8w54hbh-nixos-test-driver-pgrouting.drv
  /nix/store/hq4sxl4rp1zf6wkfzwrjw1z1ipyya46l-vm-test-run-pgrouting.drv