is it possible to use flakes to build multiple other git repos but use the source checked out on my machine, not necessarily what has been committed to the repo?

example: I have a meta-repo called nix-techstack and it checks out a bunch of other repos under nix-techstack/src/ and in nix-techstack/flake.nix I am trying to define all of the packages/apps/devShells for all of the other repos in src/. will I have to put a flake.nix anywhere I want to build or can I keep it in my meta-repo?

hey folks, I have the following default.nix file and flake.nix file in my root:
default.nix:

let
    nativePkgs = import <nixpkgs> {};
    system = import ./system.nix { pkgs = nativePkgs; };
    pkgs = import <nixpkgs> system;
    llvm = pkgs.llvmPackages_16.override { stdenv = pkgs.llvmPackages_16.libcxxClang; };
    libcxxClangOverlay = final: prev: {
        stdenv = prev.stdenv.override { stdenv = llvm.libcxxClang; };
    };

    finalPkgs = import <nixpkgs> system // { overlays = [ libcxxClangOverlay ]; };
in {
    pkgs = finalPkgs;
    #pkgs.stdenv.override { stdenv = llvm.libcxxClang; };
}

flake.nix

{

  inputs = {
      toolchain = import ./.;
  };

  outputs = inputs@{ toolchain, ... }:
      {
          inherit (toolchain) pkgs;
      };

}

now when I load the flake in the repl I get this err message: error: expected a set but got a thunk at ... what am I doing wrong here?

In reply to @lxsameer:matrix.org

hey folks, I have the following default.nix file and flake.nix file in my root:
default.nix:

let
    nativePkgs = import <nixpkgs> {};
    system = import ./system.nix { pkgs = nativePkgs; };
    pkgs = import <nixpkgs> system;
    llvm = pkgs.llvmPackages_16.override { stdenv = pkgs.llvmPackages_16.libcxxClang; };
    libcxxClangOverlay = final: prev: {
        stdenv = prev.stdenv.override { stdenv = llvm.libcxxClang; };
    };

    finalPkgs = import <nixpkgs> system // { overlays = [ libcxxClangOverlay ]; };
in {
    pkgs = finalPkgs;
    #pkgs.stdenv.override { stdenv = llvm.libcxxClang; };
}

---

flake.nix

{

  inputs = {
      toolchain = import ./.;
  };

  outputs = inputs@{ toolchain, ... }:
      {
          inherit (toolchain) pkgs;
      };

}

now when I load the flake in the repl I get this err message: error: expected a set but got a thunk at ... what am I doing wrong here?