nixos-configuration/nix-os/nix.nix

{
  lib,
  pkgs,
  ...
}:

let
  makeWrapper = "${pkgs.makeWrapper}/nix-support/setup-hook";
  # bool -> nixpkgs[]
  wrappedNixExecutables = inEnvironment: assert builtins.isBool inEnvironment; pkgs.symlinkJoin {
    name = "${pkgs.nix.name}-wrap";
    paths = [ pkgs.nix ];
    postBuild = ''
      . ${makeWrapper}
      wrapProgram $out/bin/nix-build \
        --add-flags "--log-format" \
        --add-flags "bar${lib.optionalString inEnvironment "-with-logs"}"
      wrapProgram $out/bin/nix-shell \
        --add-flags "--log-format" \
        --add-flags "bar"
    '';
  };

  wrappedNixosExecutables = pkgs.symlinkJoin {
    name = "${pkgs.nixos-rebuild.name}-wrap";
    paths = [ pkgs.nixos-rebuild ];
    postBuild = ''
      . ${makeWrapper}
      wrapProgram $out/bin/nixos-rebuild \
        --add-flags "--log-format" \
        --add-flags "bar"
    '';
  };


  wrappedNix = (pkgs.symlinkJoin {
    name = "wrappedNix-${pkgs.nix.version}";
    paths = [ pkgs.nix ] ++ [( wrappedNixExecutables false )];
  }).overrideAttrs {
    version = pkgs.nix.version;
    passthru.meta = pkgs.nix.meta;
  };
in {
  config = {
    nix.package = wrappedNix;
    environment.systemPackages = lib.map (lib.hiPrio) [
      (wrappedNixExecutables true)
      wrappedNixosExecutables
    ];
  };
}