In reply to @arianvp:matrix.org

I have

  nixConfig = {
    substituters = [ "https://cache.garnix.io" ];
    trusted-public-keys = [ "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=" ];
  };

in my flake and I accepted the options

but nix show-config doesnt show the settings in the shell
:

(nix:shell-env) Arians-MacBook-Pro:server-optimised-nixos arian$ nix show-config
accept-flake-config = false
access-tokens = 
allow-dirty = true
allow-import-from-derivation = true
allow-symlinked-store = false
allow-unsafe-native-code-during-evaluation = false
allowed-impure-host-deps = /System/Library /bin/sh /dev /usr/lib
allowed-uris = 
allowed-users = *
auto-allocate-uids = false
auto-optimise-store = true
bash-prompt = 
bash-prompt-prefix = (nix:$name)\040
bash-prompt-suffix = 
build-hook = /nix/var/nix/profiles/default/bin/nix __build-remote
build-poll-interval = 5
build-users-group = nixbld
builders = @/etc/nix/machines
builders-use-substitutes = false
commit-lockfile-summary = 
compress-build-log = true
connect-timeout = 0
cores = 12
darwin-log-sandbox-violations = false
diff-hook = 
download-attempts = 5
download-speed = 0
eval-cache = true
experimental-features = flakes nix-command
extra-platforms = x86_64-darwin
fallback = false
flake-registry = https://channels.nixos.org/flake-registry.json
fsync-metadata = true
gc-reserved-space = 8388608
hashed-mirrors = 
http-connections = 25
http2 = true
id-count = 128
ignore-try = false
impersonate-linux-26 = false
keep-build-log = true
keep-derivations = true
keep-env-derivations = false
keep-failed = false
keep-going = false
keep-outputs = false
log-lines = 10
max-build-log-size = 0
max-free = 18446744073709551615
max-jobs = 1
max-silent-time = 0
min-free = 0
min-free-check-interval = 5
nar-buffer-size = 33554432
narinfo-cache-negative-ttl = 3600
narinfo-cache-positive-ttl = 2592000
netrc-file = /etc/nix/netrc
nix-path = /Users/arian/.nix-defexpr/channels nixpkgs=flake:nixpkgs
plugin-files = 
post-build-hook = 
pre-build-hook = 
preallocate-contents = false
print-missing = true
pure-eval = true
require-sigs = true
restrict-eval = false
run-diff-hook = false
sandbox = false
sandbox-fallback = true
sandbox-paths = /System/Library/Frameworks /System/Library/PrivateFrameworks /bin/bash /bin/sh /private/tmp /private/var/tmp /usr/lib
secret-key-files = 
show-trace = false
stalled-download-timeout = 300
start-id = 56930
store = auto
substitute = true
substituters = https://cache.nixos.org/
sync-before-registering = false
system = aarch64-darwin
system-features = benchmark big-parallel nixos-test
tarball-ttl = 3600
timeout = 0
trace-function-calls = false
trace-verbose = false
trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
trusted-substituters = 
trusted-users = root arian
use-case-hack = true
use-registries = true
use-sqlite-wal = true
user-agent-suffix = 
warn-dirty = true

 flake.nixosConfigurations."naked-oci" = withSystem "aarch64-linux" (ctx@{ pkgs,config, inputs', ... }:
    inputs.nixpkgs.lib.nixosSystem {
      # Expose `packages`, `inputs` and `inputs'` as module arguments.
      # Use specialArgs permits use in `imports`.
      # Note: if you publish modules for reuse, do not rely on specialArgs, but
      # on the flake scope instead. See also https://flake.parts/define-module-in-separate-file.html
      specialArgs = {
        packages = config.packages;
        inherit inputs inputs';
        pkgs = pkgs.pkgsCross.aarch64-multiplatform;
      };
      modules = [
        # This module could be moved into a separate file; otherwise we might
        # as well have used ctx.config.packages directly.
        ({ config, lib, packages, pkgs, ... }: {
          imports = [
    inputs.disko.nixosModules.disko
  ];
nixpkgs.hostPlatform = "aarch64-linux";

...

tried like that error: a 'aarch64-linux' with features {} is required to build '/nix/store/8zwd7397wqs1dsw6j3v11jkfaivlspc3-aarch64-unknown-linux-gnu-binutils-wrapper-2.40.drv', but I am a 'x86_64-linux' with features {benchmark, big-parallel, kvm, nixos-test, uid-range}

moots: hrnz already said it, but specifically you should just be able to set these nixos options and that's all you need, keep the rest like a non-cross system

{
  nixpkgs.buildPlatform = "x86_64-linux";
  nixpkgs.hostPlatform = "aarch64-linux";
}

In reply to @2xsaiko:tchncs.de

moots: hrnz already said it, but specifically you should just be able to set these nixos options and that's all you need, keep the rest like a non-cross system

{
  nixpkgs.buildPlatform = "x86_64-linux";
  nixpkgs.hostPlatform = "aarch64-linux";
}