Packaging GHC 9.2.4 -- with no prior experience

[Justin Garcia <purefunctor@gmail.com>]

Hi all!

I've recently come to like Guix's approach coming from Nix, and would
definitely love to be able to use it within my development spaces.

I'd love to be able to package the latest versions of PureScript compiler (
https://github.com/purescript/purescript) for Guix, although one blocker is
that the latest GHC available is 9.0, whereas we currently build PureScript
against GHC 9.2.3 exclusively; eventually, that'll get bumped up to 9.2.4,
and then 9.4.2 but that will be in the following months.

With no prior experience, I decided to try and write a package declaration
for GHC 9.2.4, which can be found here:
https://github.com/akashi-moe/akashi/blob/main/akashi/packages/haskell.scm

Note that unlike GHC 9.0, this uses the Hadrian build system packaged
alongside GHC instead of Make, which is slowly being phased out by the GHC
development team.

I got pretty far this weekend, although the package declaration fails
currently during the `validate-runpath` phase, which I assume is because of
the `install` command that I used. Given that I'm on a pretty slow machine
currently, it's rather difficult to iterate when I have to wait 1h~1h30m
between builds.

I'd greatly appreciate it if anyone wants to take a look.

Kind regards,
purefunctor