infra/nix/default.nix

{ versionsPath }:
let
  channelVersions = import versionsPath;
  mkChannelSource =
    name:
    let
      channelVersion = builtins.getAttr name channelVersions;
    in
    builtins.fetchGit {
      # Descriptive name to make the store path easier to identify
      inherit name;
      inherit (channelVersion) url ref rev;
    };
  nixPath = builtins.concatStringsSep ":" (
    builtins.map (
      elemName:
      let
        elem = builtins.getAttr elemName channelVersions;
        elemPath = mkChannelSource elemName;
        suffix = if builtins.hasAttr "suffix" elem then elem.suffix else "";
      in
      builtins.concatStringsSep "=" [
        elemName
        elemPath
      ]
      + suffix
    ) (builtins.attrNames channelVersions)
  );
  pkgs = import (mkChannelSource "nixpkgs") { };
in
{
  inherit nixPath;
  channelSources = pkgs.writeText "channels.rc" ''
    export NIX_PATH=${nixPath}
  '';
}