!ayCRiZriCVtuCUpeLp:nixos.org

Nix Cross Compiling

580 Members
128 Servers

Load older messages

SenderMessageTime
10 Feb 2025
@rhelmot:matrix.orgrhelmotdoes anyone wanna explain how the splicing internals work to me03:58:07
@artturin:matrix.orgArtturinEasy, it's just adding attrs on top of the package set03:58:47
@artturin:matrix.orgArtturinFrom other offset package sets03:59:12
@rhelmot:matrix.orgrhelmotI mean like the stuff where derivations added to specific lists in mkDerivation automatically get turned into derivations from one of the spliced pkgsets03:59:34
@artturin:matrix.orgArtturin* Easy, it's just adding attrs to package attrs on top of the package set03:59:37
@rhelmot:matrix.orgrhelmotif there's a better word for that process I'd love to hear it lol03:59:53
@artturin:matrix.orgArtturinThat's the simplest part of the whole splicing thing 04:00:39
@artturin:matrix.orgArtturinhttps://github.com/NixOS/nixpkgs/blob/f202c36babad2412fc20a061d56c1f378efa806d/pkgs/stdenv/generic/make-derivation.nix#L34604:00:41
@rhelmot:matrix.orgrhelmotas far as I can tell it pulls stuff out of drv.__spliced.pkgsSomethingSomething which is provided by splice.nix but __spliced isn't present in nix repl04:00:41
@artturin:matrix.orgArtturincallPackage gets packaged from __splicedPackages04:01:05
@artturin:matrix.orgArtturin* callPackage gets packages from __splicedPackages04:01:21
@artturin:matrix.orgArtturin* callPackage gets attrs from __splicedPackages04:01:28
@artturin:matrix.orgArtturinpkgsCross.X.__splicedPackages to access them04:01:55
@rhelmot:matrix.orgrhelmothm04:02:24
@rhelmot:matrix.orgrhelmotwhat's special about pkgsCross that causes __splicedPackages to contain the __spliced attribute but not the toplevel04:03:03
@artturin:matrix.orgArtturinhttps://github.com/NixOS/nixpkgs/blob/f202c36babad2412fc20a061d56c1f378efa806d/pkgs/top-level/splice.nix#L18104:03:36
@artturin:matrix.orgArtturin
In reply to @rhelmot:matrix.org
what's special about pkgsCross that causes __splicedPackages to contain the __spliced attribute but not the toplevel
toplevel is just normal pkgs 		04:04:06
@rhelmot:matrix.orgrhelmothmmk... so actuallySplice is adjacentPackages != null04:05:05
@rhelmot:matrix.orgrhelmothere's what I'm trying to do: I want to instantiate nixpkgs with localSystem = A and crossSystem = B, do some builds, transfer the closure onto a B machine, then do the same instantiation so that B doesn't have to do any heavy building of its own... but then import pkgs/build-support/trivial-builders/default.nix with a new stdenv which has both build and host as B so that B can do things like build config files. the problem I'm foreseeing is that it will try to splice its dependencies and end up with stuff that can only run on A. I've been struggling to construct a spliced package set that, well, effectively lies about what e.g. bash.__spliced.buildHost is and actually gives hostHost.05:14:25
@rhelmot:matrix.orgrhelmotthe reason for this task: being able to build nixbsd installer images. A here is Linux and B here is e.g. OpenBSD which doesn't have a real stdenv and can't build anything natively05:16:16
@trofi:matrix.orgtrofi loongarch64's libgcc is broken: https://github.com/NixOS/nixpkgs/pull/381016 23:18:42
12 Feb 2025
@kira:jakira.spaceKira changed their display name from kira to Kira.19:59:44
14 Feb 2025
@bitestring:matrix.orgbitestring

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
13:14:55
@bitestring:matrix.orgbitestring *

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
13:16:14
@alexfmpe:matrix.orgalexfmpeYeah, android has regressed quite a bit 16:17:18
@alexfmpe:matrix.orgalexfmpeIt worked a few years back, not sure to which extent16:17:27
@alexfmpe:matrix.orgalexfmpeFor haskell I mean16:17:43
@emilazy:matrix.orgemilynobody really puts effort into maintaining Android and iOS upstream in Nixpkgs so they don't really work16:17:53
@alexfmpe:matrix.orgalexfmpeA few months ago I found some low hanging fruit and managed to build non TH libs16:18:04
@alexfmpe:matrix.orgalexfmpehttps://github.com/NixOS/nixpkgs/pull/35554316:18:06

Show newer messages

Back to Room ListRoom Version: 6