argunix: this attribute failed at evaluation time, before any build started.
attribute: nixosConfigurations.homeautomation

nix-eval-jobs error:
error:
       … while calling the 'head' builtin
         at «github:nixos/nixpkgs/549bd84d6279f9852cae6225e372cc67fb91a4c1?narHash=sha256-hGdgeU2Nk87RAuZyYjyDjFL6LK7dAZN5RE9%2BhrDTkDU%3D»/lib/attrsets.nix:1712:13:
         1711|           if length values == 1 || pred here (elemAt values 1) (head values) then
         1712|             head values
             |             ^
         1713|           else

       … while evaluating the attribute 'value'
         at «github:nixos/nixpkgs/549bd84d6279f9852cae6225e372cc67fb91a4c1?narHash=sha256-hGdgeU2Nk87RAuZyYjyDjFL6LK7dAZN5RE9%2BhrDTkDU%3D»/lib/modules.nix:1166:7:
         1165|     // {
         1166|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1167|       inherit (res.defsFinal') highestPrio;

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

       … while evaluating definitions from `/nix/store/h9wn92hv33sizprch7fcp16lfs1k3w5j-source/nixos/modules/system/activation/top-level.nix':

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

       error:
       Failed assertions:
       - Grafana's secret key (services.grafana.settings.security.secret_key) doesn't have a default
       value anymore. Please generate your own and use a file-provider on this option! See also
       https://grafana.com/docs/grafana/latest/setup-grafana/configure-grafana/#secret_key
       for more information.

       See https://grafana.com/docs/grafana/latest/setup-grafana/configure-security/configure-database-encryption/#re-encrypt-secrets on how to re-encrypt.

       As stated in the NixOS changelog for 26.05, there's no official way to rotate.
       Either hard-code the old key ("SW2YcwTIb9zpOOhoPsMm") if your setup doesn't have any secrets in the DB that need
       special protection or perform a rotation with a 3rd-party tool
       (https://github.com/erooke/grafana-secretkey-rotation-tool/tree/d9dc788902fa5185e15cb15ce6129f7237ab6138).