error:
       … while evaluating a branch condition
         at «string»:35:5:
           34|   update = lhs: rhs: lhs // builtins.mapAttrs (n: v:
           35|     if lhs ? ${n} && builtins.isAttrs lhs.${n} && !isDrv lhs.${n}
             |     ^
           36|        && builtins.isAttrs v && !isDrv v

       … in the left operand of the AND (&&) operator
         at «string»:36:30:
           35|     if lhs ? ${n} && builtins.isAttrs lhs.${n} && !isDrv lhs.${n}
           36|        && builtins.isAttrs v && !isDrv v
             |                              ^
           37|     then update lhs.${n} v else v) rhs;

       … while evaluating definitions from `/nix/store/2a9ylipb88x2sp2xn6cg58p5xm6qamai-source/modules/transposition.nix':

       … while evaluating definitions from `/nix/store/f68mkckvknzm9992ml77l2wgznvxl0xp-source/nix/checks.nix, via option perSystem':

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

       … while evaluating definitions from `/nix/store/3vr7skkmisl7bvbmq7yshmwjka5xy8mw-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `users.users.traefik.group':

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

       error: The option `users.users.traefik.group' has conflicting definition values:
       - In `/nix/store/3vr7skkmisl7bvbmq7yshmwjka5xy8mw-source/nixos/modules/services/web-servers/traefik.nix': "traefik"
       - In `nixos@services/traefik': "podman"
       Use `lib.mkForce value` or `lib.mkDefault value` to change the priority on any of these definitions.