lnl-overlay.nix

self: super:

{
  # Install overlay:
  # $ mkdir -p ~/.config/nixpkgs/overlays
  # $ curl https://gist.githubusercontent.com/LnL7/570349866bb69467d0caf5cb175faa74/raw/3f3d53fe8e8713ee321ee894ecf76edbcb0b3711/lnl-overlay.nix -o ~/.config/nixpkgs/overlays/lnl.nix
  userPackages = super.userPackages or {} // {

    # Example:
    hello = self.hello;
    # add more packages here...

    # Default packages:
    # cacert = self.cacert;
    # nix = self.nix;  # don't enable this on multi-user.

    nix-rebuild = super.writeScriptBin "nix-rebuild" ''
      #!${super.stdenv.shell}
      if ! command -v nix-env &>/dev/null; then
          echo "warning: nix-env was not found in PATH, add nix to userPackages" >&2
          PATH=${self.nix}/bin:$PATH
      fi
      exec nix-env -f '<nixpkgs>' -r -iA userPackages "$@"
    '';

  };
}

@lilyball It's working now! thanks for the explanation 👍