Without this patch merging options like
services.xserver.windowManager.xmonad.extraPackages
results in the evaluation error:
error: value is a list while a set was expected, at nixpkgs/lib/options.nix:77:23
With this patch we get the desired merging behaviour that just concatenates the
resulting package lists.
(cherry picked from commit 6e99f9fdecb1f28308c8e0aed0fc851737354864)
Co-Authored-By: Silvan Mosberger <contact@infinisil.com>