default.nix

{localSystem ? builtins.currentSystem, ...} @ args: let
  external_sources = import ./nix/sources.nix;

  nixpkgs_import_args = {
    inherit localSystem;
    config = {};
  };
  nixpkgs = import external_sources.nixpkgs nixpkgs_import_args;

  # To use bazelisk, not Bazel
  devShell =
    (nixpkgs.buildFHSEnv {
      name = "bazel_toolchains_explained-shell";

      targetPkgs = pkgs: (with pkgs; [
        alejandra
        bashInteractive
        bazelisk
        bazel-buildtools
        cocogitto
        git
        helix
        niv
        statix
        # Required by downloaded bazel
        zlib
      ]);

      runScript = nixpkgs.writeScript "bazel_toolchains_explained-shell-init.sh" ''
        cat <<EOF > user.bazelrc
        # Bazel from nix fails processing of repo-rules
        # without this being set (sic!)
        # TODO: Investigate further.
        # (/bin:/usr/bin are for the benefit of the 'hermetic' gcc toolchain...)
        common --action_env='PATH=/bin:/usr/bin:$PATH'
        startup --output_user_root=$PWD/bazel-user-root/
        EOF
        exec bash
      '';
    })
    .env;
in {
  inherit devShell nixpkgs;
}