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/zkn66xp6sgf6cmwblnhv50d8fvhmxl5h-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `environment.etc':

       … while evaluating definitions from `/nix/store/zkn66xp6sgf6cmwblnhv50d8fvhmxl5h-source/nixos/modules/services/networking/networkmanager.nix':

       … while evaluating the option `networking.networkmanager.plugins':

       … while evaluating definitions from `/nix/store/2n0mn8kgwac46i03hshsll8i9hr00i9b-source/machines/turingmachine/modules/networkmanager':

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

       error: 'networkmanager-vpnc' has been removed as insecure and archived upstream. Migrate to 'networkmanager-libreswan'