these 2 derivations will be built:
  /nix/store/9qlvf983lfd7hhm49wkfr1gg4f4lxg6r-nixos-test-driver-pg_net.drv
  /nix/store/d9gxkqzn0fz0xb8ypwa447lflnr8qffd-vm-test-run-pg_net.drv