How many applications on your system actually use these? Exactly zero on my system. How many applications in the world actually use these?
Popularity in application is irrelevant in judging the novelty or esotericity aspect of a programming language or construct.
Scheme is well-known and documented, the most esoteric thing in Scheme is probably still the continuations and that is pretty old news (with ample computer science history anyway).
I don't have time to tinker for hours to fix a single small issue at this point, where the added "knowledge" would be a language I'm not gonna use again anyway. I'm past that in my life.
Then you could just leave an issue describing it and the problem to the best of your understanding (possibly with pseudocode) and move on.
There are some signing lines for git for that use-case, too.
I have done so in the past and it is a fairly common approach.
But it also doesn't make it a non-esoteric package manager that is hardly used by anyone excepts its developers and some FSF approved distro users. To be clear, even Nix is esoteric for me, despite its somewhat wider usage compared to guix.
I did omit that part as I am uncertain where they sit on the novelty/esotericity scale. They are novel, but at the same time it's been over a decade already since the first of their kind became stable.