Cross-Compilation example doesn't work on Darwin

[dwt]

nix.dev/source/tutorials/cross-compilation.md

Line 205 in baf5f82

## Real-world cross compiling of a Hello World example

I'm not quite sure what the exact reason is, but in this example both paths do not work on Darwin.

Running them gives these two error messages:

❯  nix-build -A windows
error:
       … while evaluating 'strict' to select 'drvPath' on it
         at /builtin/derivation.nix:1:552:
       … while calling the 'derivationStrict' builtin
         at /builtin/derivation.nix:1:208:
       (stack trace truncated; use '--show-trace' to show the full trace)

       error: i686 Linux package set can only be used with the x86 family.

~/C/P/nix/tutorial/cross-compilation  ⛵️ mkk-itsc-dev (default)
❯  nix-build -A rpi
error:
       … while evaluating 'strict' to select 'drvPath' on it
         at /builtin/derivation.nix:1:552:
       … while calling the 'derivationStrict' builtin
         at /builtin/derivation.nix:1:208:
       (stack trace truncated; use '--show-trace' to show the full trace)

       error: Don't know how to run armv6l-unknown-linux-gnueabihf executables.

Is this something that is entirely not possible on Darwin, or is there just some additional configuration needed?