RE: Highlight tabulated and trailing whitespace

[Drew Adams]

Where is that variable supposed to come from?
I don't see it with vanilla Emacs 26 (`emacs -Q').

Perhaps you need to load some library first, so
it becomes defined.

And perhaps it's actually a function?  If not,
why do you bother to bind it to `n', which isn't
modified anywhere?  Is it only to have a shorter
variable name when you refer to the value (i.e.,
instead of referring to `display-cycle-stae')?
Not clear to me what you're trying to do.

> Debugger entered--Lisp error: (void-variable display-cycle-state)
>   (let ((n display-cycle-state))
> 
> > (let ((n display-cycle-state))
> >   (pcase n ...