I created a specialisation and inherited the config which had both plasma turned on and it failed with
┃ error: The option `specialisation.plasma6.configuration.environment.sessionVariables.KPACKAGE_DEP_RESOLVERS_PATH' has conflicting definition values:
┃ - In `/nix/store/2kncqm75gqnxkwhh51av36fs4daws7gh-source/flake.nix': "/nix/store/2xcgz45yzqr4y5b2vinp0x1mxihz34ix-frameworkintegration-5.245.0/libexec/kf6/kpackagehandlers"
┃ - In `/nix/store/2kncqm75gqnxkwhh51av36fs4daws7gh-source/nixos/modules/services/x11/desktop-managers/plasma5.nix': "/nix/store/mh91n84z55pqddw0853m6wkyka9z7nrs-frameworkintegration…
┃ Use `lib.mkForce value` or `lib.mkDefault value` to change the priority on any of these definitions.
I created a specialisation and inherited the config which had both plasma turned on and it failed with