In reply to @rhelmot:matrix.org
what's special about pkgsCross that causes __splicedPackages to contain the __spliced attribute but not the toplevel

Hi, can anyone please help me how to get started on cross-compilation. Documentation is very confusing and scattered across multiple places. I want to get GHC compiler than can compile my Haskell code to both ARM64 Linux and ARM64 Android. However I do not know where to get started. I tried the following flake.nix

{
  description = "Haskell Playground";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
  };

  outputs =
    {
      self,
      nixpkgs,
    }:
      let
        pkgsBuildSystem = import nixpkgs {
          localSystem = "x86_64-linux"; # buildPlatform
          config = {
            android_sdk.accept_license = true;
            allowUnfree = true;
          };
        };
        pkgs = pkgsBuildSystem.pkgsCross.aarch64-android-prebuilt;
        hs = pkgs.haskell.packages."ghc966"; # need to match Stackage LTS version from stack.yaml resolver
        ghc = hs.ghc.override {
          enableRelocatedStaticLibs = true;
          enableShared = true;
        };
        buildDependencies = with pkgs; [
          # --- System ---
          zlib

          # Haskell deps
          stack
          ghc # GHC compiler in the desired version (will be available on PATH)
        ];
      in
      {
        formatter = pkgs.nixfmt-rfc-style;
        packages.aarch64-android.default = pkgs.mkShell {
          buildInputs = [ ];
          nativeBuildInputs = buildDependencies;
          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath buildDependencies;
        };
      };
}

However nix develop fails with

./zconf.h:446:14: fatal error: 'sys/types.h' file not found

Hi, can anyone please help me how to get started on cross-compilation. Documentation is very confusing and scattered across multiple places. I want to get GHC compiler than can compile my Haskell code to both ARM64 Linux and ARM64 Android. However I do not know where to get started. I tried the following flake.nix

{
  description = "Haskell Playground";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
  };

  outputs =
    {
      self,
      nixpkgs,
    }:
      let
        pkgsBuildSystem = import nixpkgs {
          localSystem = "x86_64-linux"; # buildPlatform
          config = {
            android_sdk.accept_license = true;
            allowUnfree = true;
          };
        };
        pkgs = pkgsBuildSystem.pkgsCross.aarch64-android-prebuilt;
        hs = pkgs.haskell.packages."ghc966"; # need to match Stackage LTS version from stack.yaml resolver
        ghc = hs.ghc.override {
          enableRelocatedStaticLibs = true;
          enableShared = true;
        };
        buildDependencies = with pkgs; [
          zlib
          stack
          ghc # GHC compiler in the desired version (will be available on PATH)
        ];
      in
      {
        formatter = pkgs.nixfmt-rfc-style;
        packages.aarch64-android.default = pkgs.mkShell {
          buildInputs = [ ];
          nativeBuildInputs = buildDependencies;
          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath buildDependencies;
        };
      };
}

However nix develop fails with

./zconf.h:446:14: fatal error: 'sys/types.h' file not found

In reply to @alexfmpe:matrix.org
You might want to try haskell.nix in the meantime

In reply to @reckenrode:matrix.org
It’s also such a bad idea due to App Store rules. You’re better off using xcodenv.

In reply to @emilazy:matrix.org
nobody really puts effort into maintaining Android and iOS upstream in Nixpkgs so they don't really work

Hello. I am trying to clean up my build process. I am attempting to use the arm-embedded cross pkg. My derivation looks something like

{
  pkgs,
  stdenv,
  optLevel ? "debug",
}:

stdenv.mkDerivation {
  nativeBuildInputs = with pkgs.pkgsBuildHost; [meson ninja gnused srecord];

  name = "Jordan";
  src = pkgs.lib.cleanSource ./.;
  doCheck = false;

  mesonBuildType = optLevel;
  dontStrip = true;
  strictDeps = true;
}

and then it is called with

default = pkgs.pkgsCross.arm-embedded.callPackage ./default.nix {};

This fails with the error

error: attribute 'version' missing
       at /nix/store/1d49vqvzrcx28yjj0rrwxr2dfy15rkp6-source/pkgs/os-specific/linux/systemd/default.nix:119:59:
          118|     # assumes hard floats
          119|     && (stdenv.hostPlatform.isAarch -> lib.versionAtLeast stdenv.hostPlatform.parsed.cpu.version "6")
             |                                                           ^
          120|     # see https://github.com/NixOS/nixpkgs/pull/194149#issuecomment-1266642211

The build target is armv6m, and I am building on x86. Is there some way to provide it the info it needs?

Note that if I instance a dedicated cross instance with

armPkgs = import nixpkgs { crossSystem = { config = "armv6m-none-none-eabi"; libc="newlib"; }; };
armPkgs.callPackage ./default.nix {};

It almost works (it gets to the build stage but hits an error I've not seen with the arm-embedded compiler), but it requires compiling GCC from source.