Support for withExtraComponents option for packages

[jakenotjay]

Google cloud doesn't include many of the subcomponents by default on install, and when installed via a package manager, doesn't allow you to add any more components:

gcloud components install pubsub-emulator
ERROR: (gcloud.components.install) You cannot perform this action because this Cloud SDK installation is managed by an external package manager.
Please consider using a separate installation of the Cloud SDK created through the default mechanism described at: https://cloud.google.com/sdk/

Of course, I can get around this currently by adding the following to tasks:

tasks = {
    "google:install-gcloud" = {
      exec = ''
        curl https://sdk.cloud.google.com > install.sh
        bash install.sh --disable-prompts --install-dir=$HOME
      '';
      before = [ "google:add-credentials" ];
      # status only run if 1 is returned, so we can check if gcloud command is available, if we return 0, it will not run
      status = ''
        if ! command -v gcloud &> /dev/null; then
          exit 1
        else
          exit 0
        fi
      '';
    };

    "google:install-pubsub-emulator" = {
      exec = "gcloud components install pubsub-emulator";
      before = [ "devenv:enterShell" ];
      after = [ "google:install-gcloud" ];
    };
};

However, nix has support for withExtraComponents as can be seen here NixOS/nixpkgs#99280

[sandydoo]

However, nix has support for withExtraComponents as can be seen here NixOS/nixpkgs#99280

So why not use that?

{ pkgs, ... }: {
  packages = [ 
    (pkgs.google-cloud-sdk.withExtraComponents [ pkgs.google-cloud-sdk.components.pubsub-emulator ])
  ];
}

Or am I missing something here?