# coresimple.nix
{... }:

{
  programs = {
    git = {
      enable = false;
    };
  };
}

#coresimple2.nix
{... }:

{

  imports = [ ./coresimple.nix ];
  programs = {};
}

# why does the repl show coresimple2 programs as {} instead of with git?
# $ nix repl
# Welcome to Nix version 2.3.2. Type :? for help.

# nix-repl> (import ./coresimple2.nix {}).programs
# { }