system attribute missing in derivation

[chrichrichri]

Hello,

I am trying to install a package I created using dream2nix (from a python package) inside a docker container running nix. The docker image is derived from nix docker image using a flake similar to this one found here. Everything works fine, until I try to install the package generated by dream2nix:

extraPkgs = with pkgs; [
  <input>.packages.${pkgs.system}.<my_package_name>
];

This error shows up. It seems in the derivation the system attribute is missing, but I was not able to find how to add it. Can anyone give a hint? Thanks!

[ERROR]    error: attribute 'system' missing
[ERROR]   
[ERROR]   at /nix/store/pk6hi49dmdbspimwxr64abvc0frz2wjr-source/docker.nix:180:25:
[ERROR]   
[ERROR]   179|             outPath = "${drv}";
[ERROR]   180|             system = "${drv.system}";
[ERROR]   |                         ^
[ERROR]   181|             type = "derivation";
[ERROR]  Child process exited with error code: 1

[DavHau]

You could set public.system in your dream2nix module. Mayeb we should have this by default. Feel free to open a PR

[chrichrichri]

Thank you that helped. I would be glad to open a PR - but honestly I am not sure if I would actually help with it since I am not so good at nix... :(