Best way to not recompile linux-rpi

Help
1

linux-rpi has been removed from nixpkgs. How to prevent recompilation on nixpkgs update but keep pkgs up to date?

Freezing nixpkgs didn’t help.

    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixpkgs-rpi.url = "github:NixOS/nixpkgs?rev=d233902339c02a9c334e7e593de68855ad26c4cb";
    nixos-hardware = {
      url = "github:NixOS/nixos-hardware/master";
      inputs.nixpkgs.follows = "nixpkgs-rpi";
    };
2

Did you take a look at recent posts?