error:
       … while evaluating the attribute 'drvPath'
         at «https://releases.nixos.org/nixpkgs/nixpkgs-26.11pre1089329.ca1659429c95/nixexprs.tar.xz?narHash=sha256-Xdc4viyLXXA3qos9fo2Ezb%2BJxRasKk99tSasmSAdnSc%3D»/lib/customisation.nix:416:11:
          415|         // {
          416|           drvPath =
             |           ^
          417|             assert condition;

       … while calling the 'derivationStrict' builtin
         at «nix-internal»/derivation-internal.nix:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating the option `driverConfiguration.containers.server.start_script':

       … while evaluating definitions from `/nix/store/3kqc77svnw8jjw7x2lam368lncr0pfkv-source/nixos/lib/testing/driver-configuration.nix':

       … while evaluating definitions from `/nix/store/3kqc77svnw8jjw7x2lam368lncr0pfkv-source/nixos/modules/virtualisation/nspawn-container':

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

       … while evaluating definitions from `/nix/store/3kqc77svnw8jjw7x2lam368lncr0pfkv-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `containers.server.services.caddy.configFile':

       … while evaluating the option `containers.server.services.caddy.virtualHosts."id.test.clan".extraConfig':

       … while evaluating the option `containers.server.clan.core.vars.generators.cert-id.files."id.fullchain.crt".path':

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

       error: File 'id.fullchain.crt' at 'per-machine/server/cert-id' does not exist. Try running 'clan vars generate' first.