typedef struct packed {
  logic foo;
} some_struct_t;

module child ();
  logic a;
  assign a = bar.foo;
  // note that "foo" can be replaced with any string,
  // and the same error occurs
endmodule

module parent 
#(
  parameter some_param = 0
)
(
);
  some_struct_t bar;
  child c ();
endmodule

module top ();
  // The parameter must be anything other than the default
  parent #( 1 ) p ();
endmodule

 $ verilator --cc --top-module top struct_bug.v
%Error: Verilator internal fault, sorry.  Consider trying --debug --gdbbt
%Error: Command Failed /usr/local/bin/verilator_bin --cc --top-module top struct_bug.v