pkgs/top-level assertion failed

[AramMarkarov]

Here is the output when attempting a rebuild after having updated the flake.

error:
       … while calling the 'head' builtin
         at /nix/store/k8nkf470zpidpa5nh76lh2x6rxfzpwa4-source/lib/attrsets.nix:1574:11:
         1573|         || pred here (elemAt values 1) (head values) then
         1574|           head values
             |           ^
         1575|         else

       … while evaluating the attribute 'value'
         at /nix/store/k8nkf470zpidpa5nh76lh2x6rxfzpwa4-source/lib/modules.nix:846:9:
          845|     in warnDeprecation opt //
          846|       { value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          847|         inherit (res.defsFinal') highestPrio;

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

       … while evaluating definitions from `/nix/store/k8nkf470zpidpa5nh76lh2x6rxfzpwa4-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `assertions':

       … while evaluating definitions from `/nix/store/2cdyih09cp3b07kxzfwk7pa9w1s88mvh-source/nixos/common.nix':

       … while evaluating the option `home-manager.users.aramjonghu.assertions':

       … while evaluating definitions from `/nix/store/jq5wa4csd3rb6xzixhzqav327f9bsc1v-source/wrappers/_shared.nix':

       … while evaluating the option `home-manager.users.aramjonghu.programs.nixvim':

       … while evaluating definitions from `/nix/store/jq5wa4csd3rb6xzixhzqav327f9bsc1v-source/modules/top-level/files':

       … while evaluating the module argument `pkgs' in "/nix/store/jq5wa4csd3rb6xzixhzqav327f9bsc1v-source/modules/top-level/files":

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

       error: assertion '(((builtins).isAttrs localSystem) -> (! ((localSystem) ? parsed)))' failed
       at /nix/store/k8nkf470zpidpa5nh76lh2x6rxfzpwa4-source/pkgs/top-level/default.nix:51:1:
           50| # of package sets.
           51| assert builtins.isAttrs localSystem -> !(localSystem ? parsed);
             | ^
           52| assert builtins.isAttrs crossSystem -> !(crossSystem ? parsed);

I have checked everywhere for a couple days, and I am convinced I am still missing something. If I am not, I report this issue as seen above. It started when attempting a rebuild on Feb 3rd around 10 am CET Amsterdam.
Thanks a lot for the great work!

[MattSturgeon]

This was discussed previously in #2966, you can find workarounds there.

I've opened #2968 to fix this early, as #2964 probably won't be merged for a little while.