iverilog/ivtest/ivltests/task_nonansi_fail3.v

// Check that declaring a variable multiple times for a signal that was
// previously declared as a non-ANSI task output port is an error.

module test;

  task t;
    output x;
    reg x;
    reg x;
    $display("FAILED");
  endtask

  reg y;
  initial t(y);

endmodule