Init

nix flake new project -t github:divnix/nosys

Usage

# flake.nix
{
  inputs.nosys.url = "github:divnix/nosys";
  # file with list of systems: ["x86_64-linux" /* ... */ ]
  inputs.systems.url = "path:./flake/systems.nix";
  inputs.systems.flake = false;

  outputs = inputs @ {
    nosys,
    nixpkgs, # <---- This `nixpkgs` still has the `system` e.g. legacyPackages.${system}.zlib
    ...
  }: let outputs = import ./flake/outputs.nix;
     in nosys inputs outputs;
}

Just like a regular outputs functor:

# ./flake/outputs.nix
{
  self,
  nixpkgs, # <---- This `nixpkgs` has systems removed e.g. legacyPackages.zlib
  ...,
}: let
  inherit (nixpkgs.legacyPackages) pkgs;
in {
  # system dependant outputs
  devShells.default = self.devShells.dev;
  devShells.dev = pkgs.mkShell {
    buildInputs = with pkgs; [/* ... */];
  };

  # attributes prefixed with 1 (`_`) are kept system independant and the leading `_` is removed
  _lib.f = x: x;
  # attributes with 2 (`__`) underscores are passed through unmodified
  __functor = self: self.lib.f;

}

Systems

The systems can be a Nix list of systems or a path to a nix file with one. This means if you wish, you can even point to the file as a flake input, so that downstream can modify the systems with follows.

nosys will use its own defaults if no flake input named systems exist. You can also simply override systems as a list:

nosys (inputs' // {systems = ["x86_64-darwin"];}) # ({self, ...}:

Cross Compilation

For advanced cases like cross-compilation the system's are still available in the usual place when needing to reference a different system than the one currently being defined.