uneeded builds when using binfmt for a crossSystem

[meck]

I'm cross compiling a system for armv7 and trying to use disko to write an sd-card.

In the Im doing a writeShellScript that references ubootAmx335xEVM (an armv7 only build). and adding to environment.systemPackages.

I'm using binfmt while building the sdcard

disko.imageBuilder = {
  enableBinfmt = true;
  pkgs = pkgs.buildPackages;
  kernelPackages = pkgs.buildPackages.linuxPackages_latest;
};

When running the build (on an x86 host) the following line in make-disk-image.nix seems to try to build ubootAmx335xEVM using x86 gcc which fails. https://github.com/nix-community/disko/blob/8d6dd03a1cfc1783407e4f738166cab015621d21/lib/make-disk-image.nix#L123

The issue can be workaround by doing:

environment.systemPackages = lib.mkIf (pkgs.stdenv.hostPlatform == "armv7l-linux") [
  update-bootloader
];

However it seems a lot of unnecary packages ar build in this situation when refrencing systemToInstallNative.config.system.build.etc just to get the udev rules.