%Error-UNSUPPORTED: t/t_mod_mod.v:10:3: Unsupported: module decls within module decls
   10 |   program p_in_m();
      |   ^~~~~~~
                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
%Error-UNSUPPORTED: t/t_mod_mod.v:12:3: Unsupported: program decls within module decls
   12 |   interface i_in_m();
      |   ^~~~~~~~~
%Error-UNSUPPORTED: t/t_mod_mod.v:14:1: Unsupported: interface decls within module decls
   14 | endmodule
      | ^~~~~~~~~
%Error-UNSUPPORTED: t/t_mod_mod.v:19:3: Unsupported: interface decls within interface decls
   19 |   program p_in_i();
      |   ^~~~~~~
%Error-UNSUPPORTED: t/t_mod_mod.v:21:1: Unsupported: program decls within interface decls
   21 | endinterface
      | ^~~~~~~~~~~~
%Error: Exiting due to