Cannot run deploy script from different OS (Darwin)

[blackxored]

nix run .#nixosConfigurations.svc-mtx01.config.microvm.deploy.rebuild 
error: unable to execute '/nix/store/3h6bazmwjfxn26ypl4jsjswsv7pyypfx-microvm-rebuild/bin/microvm-rebuild': Exec format error

This has been an issue since I started using microvm.nix, and I might have talked about on Matrix, but don't remember.
Essentially, the problem is if I run the rebuild from Darwin I get an exec format error, this is because the script ends up with this shebang:

/nix/store/3hgg7pr65imdrifqqh3flg3arvkc2r22-bash-5.3p3/bin/bash

which is:

file /nix/store/3hgg7pr65imdrifqqh3flg3arvkc2r22-bash-5.3p3/bin/bash
/nix/store/3hgg7pr65imdrifqqh3flg3arvkc2r22-bash-5.3p3/bin/bash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /nix/store/7nbi22pcc92y2fqbkyp7h3srvvklmckb-glibc-2.40-224/lib/ld-linux-x86-64.so.2, BuildID[sha1]=1dd89254fa83163d4d12a8e15616116e31c7529e, for GNU/Linux 3.10.0, not stripped

as opposed to:

file $(which bash)
/nix/store/in4yc03diyvs2n2wgf3nva4hbvml8v1j-bash-interactive-5.3p9/bin/bash: Mach-O 64-bit arm64 executable, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL|PIE>

The microvm-rebuild script should use the host platform's bash.

[SuperSandro2000]

Did you try adjusting vmHostPackages for your cross use case?

[blackxored]

I have not, first time I hear of this option, I don't think it's documented anywhere?

[SuperSandro2000]

https://microvm-nix.github.io/microvm.nix/microvm-options.html#microvmvmhostpackages or via NüschtOS Search https://search.nüschtos.de/?query=vmHostPackages&option_scope=10&option=microvm.vmHostPackages

[blackxored]

Where would I put this exactly? I do not want to import the microvm module on my Darwin host as it has no use (or is it even possible).

[SuperSandro2000]

Next to the other microvm optons. It should influence the scripts used to start the microvm.
You probably want something like vmHostPackages = import nixpkgs { system = "aarch64-darwin"; }

If that doesn't work than that's a bug and we would love to get a PR to fix that but due to very limited time, I cannot work on that right now myself.

[blackxored]

Next, to vcpu and mem, I think I put it there, and it gave me a "no such option" error, that's why I asked and thought it would be on the host module instead.

[23b00t]

@blackxored Can you share your relevant config? I can't see how "no such option" for microvm.vmHostPackages is even possible

[blackxored]

I was using an old fork I made before this option was made available 😓.
Still doesn't work as setting the option throws this error:

Refusing to evaluate package 'virtiofsd-1.13.3' in /nix/store/bing5zyrylvp5s1bwwbzz89w1vn589jx-source/pkgs/by-name/vi/virtiofsd/package.nix:52 because it is not available on the requested hostPlatform:
         hostPlatform.system = "aarch64-darwin"