> in trying to build a Docker image for ARM64 (aarch64-linux), I am
> hitting errors of the kind
> 
>   "package git-annex@10.20230926 does not support aarch64-linux"
> 
> There doesn't seem to be anything specifically in the package
> definitions that precludes building for aarch64-linux, so I suspect it's
> either a dependency or the build system that lacks the required support.

Git-annex uses the haskell-build-system which requires GHC, the only
modern haskell compiler. Unfortunately GHC is only packaged for
i686-linux and x86_64-linux in Guix.

> How would I go about debugging such issues? Maybe the causes are simple
> and I can fix them. But I don't even know where to start.

Maybe someone else can give more general or Guix specific advice on
finding out the cause of such problems, but I believe that in this case
the fix would just be packaging GHC for aarch64-linux. It should[1] be
possible but it will require some work.

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/platforms

- Saku