Error when running nix build

Hi, I’m trying to use nixCats to convert my own neovim config, however when I do nix build which as far as I know should build the flake in the current directory, errors with the following error:

warning: Git tree '/home/nico/.dotfiles/neovim-update' is dirty
error:
       … while evaluating a branch condition

         at /nix/store/y3wcwikr0fl9jysgn2fmg9kwf7sp3s6d-source/pkgs/stdenv/booter.nix:99:7:

           98|     thisStage =
           99|       if args.__raw or false
             |       ^
          100|       then args'

       … in the right operand of the update (//) operator

         at /nix/store/y3wcwikr0fl9jysgn2fmg9kwf7sp3s6d-source/pkgs/stdenv/booter.nix:84:7:

           83|       { allowCustomOverrides = index == 1; }
           84|       // (stageFun prevStage))
             |       ^
           85|     (lib.lists.reverseList stageFuns);

       (stack trace truncated; use '--show-trace' to show the full trace)

       error: getting status of '/nix/store/1gaayqx0zsc2j60nacyf970v4a9dmb39-source/overlays': No such file or directory

Here is the flake in the same directory (with all commented lines removed):

{
  description = "A Lua-natic's neovim flake, with extra cats! nixCats!";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    nixCats.url = "github:BirdeeHub/nixCats-nvim/8a59925";
  };

  outputs = { self, nixpkgs, flake-utils, nixCats, ... }@inputs: let
    utils = nixCats.utils;
    luaPath = "${./.}";
    forEachSystem = flake-utils.lib.eachSystem flake-utils.lib.allSystems;
    extra_pkg_config = {
      allowUnfree = true;
    };



    system_resolved = forEachSystem (system: let
      standardPluginOverlay = utils.standardPluginOverlay;


      dependencyOverlays = [ (utils.mergeOverlayLists nixCats.dependencyOverlays.${system}
      ((import ./overlays inputs) ++ [
        (utils.standardPluginOverlay inputs)
      ])) ];
    in { inherit dependencyOverlays; });
    inherit (system_resolved) dependencyOverlays;
    categoryDefinitions = { pkgs, settings, categories, name, ... }@packageDef: {

      propagatedBuildInputs = {
        generalBuildInputs = with pkgs; [
        ];
      };

      lspsAndRuntimeDeps = {
        general = with pkgs; [
          universal-ctags 
          ripgrep 
          fd 
          gcc
          nix-doc 
          nil 
          lua-language-server 
          nixd
          stylua
          prettierd
          lazygit
          checkstyle
          languagetool-rust
          nodePackages.typescript-language-server
          emmet-ls
          clang-tools
          zls
          eslint_d
          marksman
          nodePackages.pyright
        ];
      };

      startupPlugins = {
        lazy = with pkgs.vimPlugins; [
          lazy-nvim
        ];
        general = {
          gitPlugins = with pkgs.neovimPlugins; [
            hlargs
          ];
          vimPlugins = with pkgs.vimPlugins; [
            neodev-nvim
            autoclose-nvim
            comment
            luasnip
            nvim-cmp
            friendly-snippets
            cmp-nvim-lsp
            cmp_luasnip
            cmp-nvim-lua
            cmp-nvim-lsp-signature-help
            cmp-path
            cmp-buffer
            conform-nvim
            nvim-dap
            nvim-treesitter-textobjects
            nvim-treesitter.withAllGrammars
            gitsigns-nvim
            lazygit-nvim
            fidget-nvim
            nvim-lspconfig
            neodev-nvim
            rustaceanvim
            lualine-nvim
            nvim-web-devicons
            neo-tree-nvim
            none-ls-nvim
            vim-sleuth
            plenary-nvim
            telescope-nvim
            telescope-undo-nvim
            telescope-ui-select-nvim
            telescope-fzf-native-nvim
            vimtex
            todo-comments-nvim
            trouble-nvim
            undotree
          ];
        };
        themer = with pkgs.vimPlugins;
          (builtins.getAttr packageDef.categories.colorscheme {
              "onedark" = onedark-nvim;
              "catppuccin" = catppuccin-nvim;
              "tokyonight" = tokyonight-nvim;
            }
          );
      };

      optionalPlugins = {
        custom = with pkgs.nixCatsBuilds; [ ];
        gitPlugins = with pkgs.neovimPlugins; [ ];
        general = with pkgs.vimPlugins; [ ];
      };

      environmentVariables = {
        test = {
          subtest1 = {
            CATTESTVAR = "It worked!";
          };
          subtest2 = {
            CATTESTVAR3 = "It didn't work!";
          };
        };
      };

      extraWrapperArgs = {
        test = [
          '' --set CATTESTVAR2 "It worked again!"''
        ];
      };

      extraPythonPackages = {
        test = (_:[]);
      };
      extraPython3Packages = {
        test = (_:[]);
      };
      extraLuaPackages = {
        test = [ (_:[]) ];
      };
    };





    packageDefinitions = {
      nixCats = { pkgs, ... }@misc: {
        settings = {
          wrapRc = true;
          configDirName = "testerstart-nvim";
          aliases = [ "vi" "vim" ];
        };
        categories = {
          lazy = true;
          generalBuildInputs = true;
          general = true;
          lspDebugMode = false;
          themer = true;
          colorscheme = "catppuccin";
          theBestCat = "says meow!!";
          theWorstCat = {
            thing'1 = [ "MEOW" "HISSS" ];
            thing2 = [
              "I LOVE KEYBOARDS"
              {
                thing3 = [ "give" "treat" ];
              }
            ];
          };
        };
      };
    };
    defaultPackageName = "nixCats";
  in

  forEachSystem (system: let
    inherit (utils) baseBuilder;
    customPackager = baseBuilder luaPath {
      inherit nixpkgs system dependencyOverlays extra_pkg_config;
    } categoryDefinitions;
    nixCatsBuilder = customPackager packageDefinitions;
    pkgs = import nixpkgs { inherit system; };
  in {

    packages = utils.mkPackages nixCatsBuilder packageDefinitions defaultPackageName;

    overlays = utils.mkOverlays nixCatsBuilder packageDefinitions defaultPackageName;

    devShell = pkgs.mkShell {
      name = defaultPackageName;
      packages = [ (nixCatsBuilder defaultPackageName) ];
      inputsFrom = [ ];
      shellHook = ''
      '';
    };

    inherit customPackager;
  }) // {


    nixosModules.default = utils.mkNixosModules {
      inherit defaultPackageName dependencyOverlays luaPath
        categoryDefinitions packageDefinitions nixpkgs;
    };
    homeModule = utils.mkHomeModules {
      inherit defaultPackageName dependencyOverlays luaPath
        categoryDefinitions packageDefinitions nixpkgs;
    };
    inherit utils categoryDefinitions packageDefinitions dependencyOverlays;
    inherit (utils) templates baseBuilder;
    keepLuaBuilder = utils.baseBuilder luaPath;
  };

}

I’m very much a noob at nix and might have made an obvious mistake, regardless thank you in advance!