I was thinking I might be able to beg time to fiddle on a Win10 machine at the weekend (if nobody else had helped) but I totally forgot about it when I had the chance.
I know the (often linked) XScreenSaver is officially dis-supported for Windows by the author's request, but I know of no reason why the fortune-mod should not be trivially compilable upon that platform. At its core, I'm not even sure why it would ever need much more than the stdio library, actually, but I suppose it's easier[1] or a GUI-aware level of cruft. And while not exactly barest-of-bones ANSI C modules (well, Internationalisation has probably been revamped plenty of times since I first touched a C compiler, back when I only really worried about £s not looking like #s if they didn't have to) surely they're amongst the default-on optional extras in any decent compiler these days.
Been a while since I so directly used MSYS2/MingW(64?), though. Could have even been Minimal SYStem
One back when I did. Too many alternate IDEs to flit between that do all the package-management near invisibly or do an 'install all' from the get go. And when I want to base myself or prototype something I retreat into good old (inefficient but lovable for it) mostly-cross-platform Perl scripting.
...erm, anyway. This is all why I wanted a fresh install on the right platform to see what the problem might be. This was not actually supposed to such a long ramble about how I have no solution yet. Just to say that I (as well as wierd) was not ignoring the question, but I remain unable to help out directly. Or at all, at possibly. At least until my next opportunity to grab use of a Win10 machine.
Still, happy to further Bump the issue, or perhaps enrage others enough by my stupid comments that they make more valid contributions to counter them!
[1] If it weren't for multiline fortune-entries, I could bash up a
Batch File 'random line picker' for you. With a standard Perl port, I would have sufficient to regex multilines out, and probably wouldn't even need to activate advanced internationalisation options most of the time between ripping from source and shoving and shoving to console, though even then the codepageband multibyte conversions could do with some finessing. If I wanted to pop up things in a window, rather than console, then I'd add the Tkx package to the Perl header and be done with it. But I get the impression that 'getting fortunes displayed' is not the end result you seek, but just an exercise in getting
something to work in a way you can understand.