Drive/monitor EEnet using virtual interface

I am trying to write a UVM testbench for a block using EE_pkg::EEnet inputs/outputs, but it is not working. Is there something I'm missing for how to use interfaces with EEnet ports?

When I try to create an interface it does not compile:

import EE_pkg::*;
interface block_interface(input bit clk);
  EEnet input_signal;

  clocking driver_cb @ (posedge clk);
    output input_signal;
  endclocking

  modport driver_mp (clocking driver_cb);
endinterface

  output input_signal;
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xmvlog: *E,WOUPYR (block_interface.sv,70|22): As a temporary implementation restriction, unpacked structures nettype is not permitted in this context.