Just had to try running this on Slackware 15 with the groff that is part of the install. The git source has a hardwired path to ghostscript/9.53.3/..some font. Just symlinked to the 9.55.0 present in Slackware and there we are, a pdf file, with some warnings about bookmarks and a table with zero width spacing. Impressive work.
Thanks to those responsible for this both for the book and for an example of how to produce a book with groff using the ms macros.
I kept my resume in troff from maybe late 80s until early 2017. troff is really weird, a genuinely different kind of text formatting. The fact that something as commonplace as text formatting can have such divergent methods as troff, lout and TeX has kept me looking for things like different pattern matching, something not at all like regular expressions.
And what do you find weird in troff? I see it as an early markdown, or rather, markdown as yet another take on runoff (https://en.wikipedia.org/wiki/TYPSET_and_RUNOFF). Markdown is a bit more implicit and (unless you ‘escape’ out of it using html) has fewer features, but I don’t see it as that different.
I'm aware of the Chomsky hierarchy. You can express more in a language with a grammar than one described by regular expressions.
What's weird in troff: macros aren't particularly easy. Also the necessity of mixing "semantic" macros (.PP or whatever for "here's a paragraph") with fine-grained typesetting directives. There's also some property of .troff that although the language is enough to write old school file viruses (here's something about a TeX virus: https://www.usenix.org/system/files/login/articles/73506-che..., can't find the troff virus citation), I don't think anyone has ever been able to write a troff self-replicating program. It appears you can't write a macro that puts a '.' at the beginning of the line or something like that.
I'm also aware that Stevens typeset all of this books with troff. It's very capable and unlike some other word processing systems, you can keep troff files in version control systems meaningfully.
I tried that and every recruiter wanted a word doc anyway. Didn't matter how beautiful the resume was in *roff or TeX; they couldn't quickly remove your info and put theirs at the top if you only sent them hardcopy or a PDF, so they didn't want it.
The book I learned writing networking code from, Steven's "Unix Network Programming" (https://en.wikipedia.org/wiki/UNIX_Network_Programming) was typeset in troff. The first edition (1990) at least. The later ones aren't I think. Stevens passed away in 1999.
I recall coming across many other books which mentioned "troff" in the introduction back then.
[1]: https://archive.org/details/utp_book/page/n3/mode/2up