error:
       … while evaluating a branch condition
         at «string»:25:5:
           24|     v:
           25|     if !builtins.isAttrs v || isDrv v then
             |     ^
           26|       v

       … in the left operand of the OR (||) operator
         at «string»:25:28:
           24|     v:
           25|     if !builtins.isAttrs v || isDrv v then
             |                            ^
           26|       v

       … while evaluating the option `system.build.toplevel':

       … while evaluating definitions from `/nix/store/x85g4cmcjva68vjxn3wr5j3mabvx0jk4-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `warnings':

       … while evaluating definitions from `/nix/store/x85g4cmcjva68vjxn3wr5j3mabvx0jk4-source/nixos/modules/system/boot/systemd.nix':

       … while evaluating the option `systemd.services.home-manager-pschmitt.serviceConfig':

       … while evaluating definitions from `/nix/store/5d6k9kgxfpazzb88scxx3sgcp9arq51h-source/nixos':

       … while evaluating the option `home-manager.users.pschmitt.home.file."/home/pschmitt/.config/fontconfig/conf.d/10-hm-fonts.conf".source':

       … while evaluating definitions from `/nix/store/5d6k9kgxfpazzb88scxx3sgcp9arq51h-source/modules/misc/xdg':

       … while evaluating the option `home-manager.users.pschmitt.xdg.configFile."fontconfig/conf.d/10-hm-fonts.conf".source':

       … while evaluating definitions from `/nix/store/5d6k9kgxfpazzb88scxx3sgcp9arq51h-source/modules/misc/fontconfig.nix':

       … while evaluating the option `home-manager.users.pschmitt.fonts.fontconfig.configFile.fonts.source':

       … while evaluating definitions from `/nix/store/5d6k9kgxfpazzb88scxx3sgcp9arq51h-source/modules/misc/fontconfig.nix':

       … while evaluating the option `home-manager.users.pschmitt.fonts.fontconfig.configFile.fonts.settings':

       … while evaluating definitions from `/nix/store/5d6k9kgxfpazzb88scxx3sgcp9arq51h-source/modules/misc/fontconfig.nix':

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

       error: Refusing to evaluate package 'gtk+-2.24.33' in /nix/store/x85g4cmcjva68vjxn3wr5j3mabvx0jk4-source/pkgs/by-name/gt/gtk2/package.nix:155 because it has problems:
       - broken: gtk2 will be removed because because its final release 2.24.33 happened in December 2020.
       Packages using it should be migrated to gtk3 or gtk4 before NixOS 27.05.
        (https://github.com/NixOS/nixpkgs/issues/410814)

       See also https://nixos.org/manual/nixpkgs/unstable#sec-problems
       To allow evaluation regardless, use:
       - Nixpkgs import: import nixpkgs { config = <below code>; }
       - NixOS: nixpkgs.config = <below code>;
       - nix-* commands: Put below code in ~/.config/nixpkgs/config.nix

         {
           problems.handlers = {
             "gtk+".broken = "warn"; # or "ignore"
           };
         }