message: better err msgs
diff: @@ -242,7 +242,7 @@ class ToVerilog2005Stm(ToVerilog2005Expr):
  self.visit_doc(o)
  w = self.out.write
  w("#")
  - assert len(o.val) == 1
  + assert len(o.val) == 1, o.val
  self.visit_iHdlExpr(o.val[0])
  return True
  