these 2 derivations will be built:
  /nix/store/1c8h6ng9150y0b7hwjqd7fy7v6p51bmm-nixos-test-driver-postgis.drv
  /nix/store/6yrj5g9nijkb83697bx1hvhc2y580xqk-vm-test-run-postgis.drv