chore: Add __readTree attributes on systems that need to be built

This is a temporary state (TODO added) to be picked up by the new CI
logic.

Change-Id: Id4702740ffd18325088e2a8a0c6157a8cee7ccf7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1852
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>

ops/nixos/default.nix

@@ -42,4 +42,10 @@ rec {
     nix-env -p /nix/var/nix/profiles/system --set $system
     $system/bin/switch-to-configuration switch
   '';
+
+  # Systems that should be built in CI
+  #
+  # TODO(tazjin): Refactor the whole systems setup, it's a bit
+  # inconsistent at the moment.
+  whitbySystem = (nixosFor whitby).system // { __readTree = true; };
 }

users/tazjin/nixos/default.nix

@@ -8,7 +8,7 @@ let
     configuration = lib.fix(config:
       foldl' lib.recursiveUpdate {} (map (c: c config) configs)
     );
-  }).system;
+  }).system // { __readTree = true; };
 
   caseFor = hostname: ''
     ${hostname})