[Nix-dev] override xlibs.libXft

[Sergey Mironov]

Hi. I'd like to test LCD patch on top of libXft, see if it renders fonts better
or not. To do it, I wrote the following in my config:

	nixpkgs.config = {
	  packageOverrides = pkgs: {
		...
		libXft_lcd = pkgs.xlibs.libXft.override {
		  patches = [
nixpkgs/pkgs/servers/x11/xorg/libXft-2.1.14-lcd-cleartype.patch ];
		};
		...
	  };
	};

	environment.systemPackages = with pkgs ; [
	  ...
  	  libXft_lcd
	  ...
	  ];

Unfortunately, nix says

	error: attribute `xlibs.libXft.override' missing
	(use `--show-trace' to show detailed location information)

Why is that? libXft looks like a typical result of mkDerivation but don't have
an override function - probably I am missing something. How to override then?

Thanks,
Sergey

PS
I've done the patching by dyrtyhacking
nixpkgs/pkgs/servers/x11/xorg/default.nix, and
modifying LD_LIBRARY_PATH. Well, I can't see any difference on my screen :) What
really helps to improve my fonts is the

<match target="font">
  <edit mode="assign" name="lcdfilter">
    <const>lcddefault</const>
  </edit>
</match>

clause in ~/.fonts.conf