I tried building generics-sop with various compilers.

x86_64, ghc963Binary = fails
x86_64, ghc963 = ok
x86_64, ghc928 = ok
RV64GC, ghc928 (cross-compiled from x86_64) = fails on th-abstraction (relocation R_RISCV_HI20 against 'a local symbol' can not be used when making a shared object; recompile with -fPIC)
RV64GC, ghc928 (native, booted with cross-compiled 8.10.7) = ok

All compilers except ghc963Binary were built using Nixpkgs (cross-compiled versions required a custom branch).

(Excuse the old RV64GC compiler versions. My dev board hasn't been updated in months and I don't have the patience to wait 15+ hours for a new GHC version to compile.)

  nixConfig = {
    extra-substituters = [ "https://cache.ztier.in" ];
    extra-trusted-public-keys = [ "cache.ztier.link-1:3P5j2ZB9dNgFFFVkCQWT3mh0E+S3rIWtZvoql64UaXM=" ];
  };

i think i have this setup correctly ?

In reply to @hive:the-apothecary.club
i looked through the chat and couldn't find any good binary caches, maybe i missed something, but https://github.com/misuzu/nixos-vf2/blob/master/flake.nix#L3 seems to just give a 404 ? at the very least, when trying it i'm still getting the error with ghc so i'm not sure what's going on here

so i'm trying to build with your branch, but i'm getting the error:

error: cannot bootstrap GHC on this platform ('riscv64-linux' with libc 'defaultLibc')

tau: Here is a minimal flake that at least evaluates

{
  inputs = {
    nixpkgs.url = "github:AlexandreTunstall/nixpkgs/ghc-cross";
  };

  outputs = { nixpkgs, ... }:
    {
      nixosConfigurations.riscv64 = nixpkgs.lib.nixosSystem {
        modules = [({lib, pkgs, ...}: {
          nixpkgs.crossSystem.system = "riscv64-linux";
          nixpkgs.localSystem.system = "x86_64-linux";
          environment.systemPackages = [
             pkgs.haskell.compiler.native-bignum.ghc948
          ];
          # Dummy values
          fileSystems."/".device  = lib.mkDefault "/dev/sda1";
          boot.loader.grub.device = lib.mkDefault "/dev/sda";
        })];
      };
    };
}

Maybe you can use that to figure out what is going wrong.

In reply to @hive:the-apothecary.club
i looked through the chat and couldn't find any good binary caches, maybe i missed something, but https://github.com/misuzu/nixos-vf2/blob/master/flake.nix#L3 seems to just give a 404 ? at the very least, when trying it i'm still getting the error with ghc so i'm not sure what's going on here

tau you're in luck because I was planning on writing some instructions in the shared notes (see room description) this evening.

I'll let you know when the instructions are ready.

tau Steven Keuchel fgaz the shared notes now have instructions for how to get a working GHC.

(Disclaimer: It's been a while since I first booted GHC and I haven't yet had time to properly test the instructions.)