Unclear docs in "Viewing and Deleting Historical Data"

[refaelsh]

It is stated here https://nixos-and-flakes.thiscute.world/nixos-with-flakes/other-useful-tips#viewing-and-deleting-historical-data: Due to the following issue, you need to run the gc command as per user to delete home-manager's historical data.
I don't understand what it means. Does this mean I need to run nix-collect-garbage --delete-old as root and as the user?

Please explain this to me :-)

Thanks in advance.

[ryan4yin]

If you're not using home-manager, then you can safely ignore this comment and the command.

The issue is that, sudo nix-collect-garbage --delete-old will only delete all the system-level's historical data, and sudo means your're running the command under root.

But the home-manager's historical data will remains on your system, so you should run nix-collect-garbage --delete-old without sudo, to clear all the data for your current user.

You need to run nix-collect-garbage --delete-old under all users with home-manager installed , that's why I said per user in the docs.
But Generally speaking, you will only have home-manager under your personal account, so you don't need to run this command multiple times.

[refaelsh]

I understand. Thank you very much :-)