| 13 Oct 2025 |
 Ihar Hrachyshka | no idea. I'm not really a cross expert... :) | 13:56:35 |
 matthewcroughan @fosdem | this isn't cross | 13:56:41 |
| matthewcroughan @fosdem | this is native | 13:56:42 |
| matthewcroughan @fosdem | cross works fine | 13:56:56 |
| matthewcroughan @fosdem | I have a full pkgs.nixos {} building with cross, both llvm/musl, but now I'm tackling the native case | 13:57:18 |
| Ihar Hrachyshka | I think musl is cross in a way - you cross build musl binaries with glibc build packages. It's just not arch cross.
(maybe I'm using terms incorrectly though)
| 13:57:30 |
| matthewcroughan @fosdem | Untrue in this case | 13:57:40 |
| matthewcroughan @fosdem | I've already done the cross case | 13:57:44 |
| matthewcroughan @fosdem | pkgsMusl is musl -> musl | 13:57:51 |
| matthewcroughan @fosdem | nixosConfigurations.gnu-musl = nixosConfigurations.base.extendModules {
modules = [
./musl.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-gnu");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {};
}
];
};
nixosConfigurations.gnu-musl-llvm = nixosConfigurations.base.extendModules {
modules = [
./musl-llvm.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-gnu");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {
useLLVM = true;
linker = "lld";
config = "aarch64-unknown-linux-musl";
};
}
];
};
nixosConfigurations.musl = nixosConfigurations.base.extendModules {
modules = [
./musl.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {};
}
];
};
nixosConfigurations.musl-llvm = nixosConfigurations.base.extendModules {
modules = [
./musl-llvm.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {
useLLVM = true;
linker = "lld";
config = "aarch64-unknown-linux-musl";
};
}
];
};
| 13:58:08 |
| matthewcroughan @fosdem | * nixosConfigurations.gnu-musl = nixosConfigurations.base.extendModules {
modules = [
./musl.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-gnu");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {};
}
];
};
nixosConfigurations.gnu-musl-llvm = nixosConfigurations.base.extendModules {
modules = [
./musl-llvm.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-gnu");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {
useLLVM = true;
linker = "lld";
config = "aarch64-unknown-linux-musl";
};
}
];
};
nixosConfigurations.musl = nixosConfigurations.base.extendModules {
modules = [
./musl.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {};
}
];
};
nixosConfigurations.musl-llvm = nixosConfigurations.base.extendModules {
modules = [
./musl-llvm.nix
{
nixpkgs.buildPlatform = (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl");
nixpkgs.hostPlatform = inputs.nixpkgs.lib.recursiveUpdate (inputs.nixpkgs.lib.systems.elaborate "aarch64-unknown-linux-musl") {
useLLVM = true;
linker = "lld";
config = "aarch64-unknown-linux-musl";
};
}
];
};
| 13:58:14 |
| Ihar Hrachyshka | ah I see. I haven't looked at non-static musl, only pkgsStatic (which I believe is glibc->musl cross). anyway, I'm not of help. | 13:58:34 |
| matthewcroughan @fosdem | well musl-static is the thing that's failing | 13:59:13 |
| matthewcroughan @fosdem | so is that not related to pkgsStatic? | 13:59:19 |
| Ihar Hrachyshka | pkgsStatic is musl static. (I'm confused.) | 13:59:36 |
| matthewcroughan @fosdem | The name of the derivation that is failing is musl-static-aarch64-unknown-linux-musl | 14:00:01 |
| matthewcroughan @fosdem | musl-static | 14:00:05 |
| matthewcroughan @fosdem | pkgsMusl.pkgsStatic.musl is the reproducer | 14:00:54 |
| matthewcroughan @fosdem | IDK why this ends up in the dependency graph | 14:01:33 |
| matthewcroughan @fosdem | 
Download image.png | 14:02:48 |
| matthewcroughan @fosdem | looks like somehow the gcc-wrapper needs it | 14:03:02 |
| matthewcroughan @fosdem | pkgsStatic.pkgsLLVM.musl builds just fine | 14:06:19 |
 rosssmyth | While the APIs that are being used for ${program}.withPackages pattern is very nice and egronomic, it does have a downside of not using a spliced package. So for example recently I needed Python with a package in nativeBuildInputs, but then when cross-compiled it only has Python from pkgsHostTarget, leading to an invalid executable being used at build time and then either manually using pkgsBuildBuild.python or using the spliced Python and package separately.
I wonder if there is a good way to solve this? Meaning a way to use the spliced package, as for folks not in the know of splicing it is probably confusing to see a package operate differently based upon whether you use the helpers or not. But many of these helpers are implemented with finalAttrs.finalPackage, which isn't spliced.
| 18:00:49 |
 Sandro | Can someone look at https://github.com/NixOS/nixpkgs/pull/447492 for the correct splice setup? | 22:31:54 |
 hexa | also #windows:nixos.org maybe | 23:11:28 |
| 14 Oct 2025 |
| Sandro | I did not know we had a room for that | 13:36:20 |
|  UlyssesZhan joined the room. | 23:34:39 |
| 15 Oct 2025 |
| matthewcroughan @fosdem | I haven't had any reviews on my musl/llvm PRs yet | 17:15:14 |
| matthewcroughan @fosdem |
- https://github.com/NixOS/nixpkgs/pull/451665
- https://github.com/NixOS/nixpkgs/pull/451147
- https://github.com/NixOS/nixpkgs/pull/447166
- https://github.com/NixOS/nixpkgs/pull/445833
| 17:15:37 |
| matthewcroughan @fosdem | Any takers? | 17:15:40 |
