error:
       … while calling the 'head' builtin
         at «git+https://github.com/Mic92/nixpkgs?ref=main&rev=164ce5be6315e3cdb381b8064d577efa83aa78aa&shallow=1»/lib/attrsets.nix:1719:13:
         1718|           if length values == 1 || pred here (elemAt values 1) (head values) then
         1719|             head values
             |             ^
         1720|           else

       … while evaluating the attribute 'value'
         at «git+https://github.com/Mic92/nixpkgs?ref=main&rev=164ce5be6315e3cdb381b8064d577efa83aa78aa&shallow=1»/lib/modules.nix:1149:7:
         1148|     // {
         1149|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1150|       inherit (res.defsFinal') highestPrio;

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

       … while evaluating definitions from `/nix/store/ijagngjnwfcbf7hm9fzzi3yz9y1yas07-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `warnings':

       … while evaluating definitions from `/nix/store/ijagngjnwfcbf7hm9fzzi3yz9y1yas07-source/nixos/modules/system/boot/systemd.nix':

       … while evaluating the option `systemd.services.zerotierone.serviceConfig':

       … while evaluating definitions from `/nix/store/ijagngjnwfcbf7hm9fzzi3yz9y1yas07-source/nixos/modules/system/boot/systemd.nix':

       … while evaluating the option `systemd.services.zerotierone.preStart':

       … while evaluating definitions from `/nix/store/ijagngjnwfcbf7hm9fzzi3yz9y1yas07-source/nixos/modules/services/networking/zerotierone.nix':

       … while evaluating the option `services.zerotierone.joinNetworks':

       … while evaluating definitions from `/nix/store/bpdjcb5wsxlq81xm8ksphcqq9s6m4wxy-source/clanServices/zerotier/default.nix, via option _services.allServices.clan-core-zerotier.perMachine, via option nixosModule':

       … while evaluating the option `clan.core.vars.generators.zerotier-network-zerotier-mic92.files.network-id.value':

       … while evaluating the option `clan.core.vars.generators.zerotier-network-zerotier-mic92.files.network-id.path':

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

       error: File 'network-id' of generator 'zerotier-network-zerotier-mic92' does not exist. Try running 'clan vars generate' first.