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Neither unstable, nor 20.09 can be cross compiled to armv7. I haven't tested aarch64 recently but, a few weeks back, it was just as broken.

Packages that don't cross compile anymore:

• libselinux (fixed by cpython: fix cross-compiling extension modules #98915)
• btrfs-progs (fixed by cpython: fix cross-compiling extension modules #98915)
• cifs-utils (fixed by cifs-utils: don't check for AC_FUNC_MALLOC when cross compiling #106761)
• nfs-utils (fixed by nfs-utils: pass native rpcsvc-proto to configureFlag #106763)
• mesa (fixed by mesa: find prefixed nm when cross compiling #106804)
• spidermonkey_78 (pkgsCross.armv7l-hf-multiplatform.spidermonkey_78: error: field 'ufp' has incomplete type 'user_vfp' #106947)
• gobject-introspection (possibly fixed by WIP: gobject-introspection: Support cross #88222) (still broken but has been removed from the closure)
• talloc (pkgsCross.talloc does't build anymore #106953)
• zfs

Additional context
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Simplest configuration.nix you should be able to build:

{ lib, ... }:

{
  imports = [
    <nixpkgs/nixos/modules/installer/cd-dvd/sd-image-armv7l-multiplatform.nix>
  ];

  nixpkgs = {
    crossSystem = lib.systems.examples.armv7l-hf-multiplatform;
    localSystem = { system = "x86_64-linux"; };
  };
}

(Could this become a hydra job?)

Notify maintainers

@Ericson2314 @matthewbauer

Metadata
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Maintainer information:

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