Nix derivation for building and developing sac2c from source

Use this if you need:

• To build a version of sac2c with particular inputs or build flags. Such as the latest git commit, with a a patch, or with particular build flags.
• A nix dev shell to compile sac2c

Otherwise, using sac-nix will probably be easier.

Keep in mind that building sac2c and the standard library from source takes a while.

How to use

Either use the overlay exposed as overlays.default, or directly use the packages.sac2c and/or packages.sac2c-with-stdlib.

For instance, since I need a particular version of cuda, I do the following:

let pkgs = import inputs.nixpkgs {
  localSystem.system = "x86_64-linux";
  config = {
    allowUnfree = true;
    cudaSupport = true;
    cudaVersion = 12.0;
    cudaCapabilities = [ "5.2" ];
  };

  overlays = [ inputs.sac2c-nix.overlays.default ];
};
in
  ...

See https://gitlab.sac-home.org/daanrs/internship-code/-/blob/main/flake.nix for an example.