%Error-UNSUPPORTED: t/t_randsequence_func.v:31:23: Unsupported: randsequence production function ports 31 | void func(int n) : { counts[1] += n; }; | ^ ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest %Error: t/t_randsequence_func.v:31:23: Input/output/inout does not appear in port list: 'n' 31 | void func(int n) : { counts[1] += n; }; | ^ ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance. %Error: Exiting due to