anchor.diff: -{ stdenv, fetchurl, fetchgit, pkgconfig, cmake, libiconvOrEmpty, libintlOrEmpty
  +{ stdenv, fetchurl, fetchpatch, pkgconfig, cmake, libiconvOrEmpty, libintlOrEmpty
   , zlib, curl, cairo, freetype, fontconfig, lcms, libjpeg, openjpeg
   , qt4Support ? false, qt4 ? null
   }:
  
positive.code:   poppler_glib = poppler_drv "glib" { };
  
    poppler_qt4 = poppler_drv "qt4" {
      propagatedBuildInputs = [ qt4 poppler_glib ];
      NIX_LDFLAGS = "-lpoppler";
      postConfigure = ''
  
negative.code: let
    version = "0.28.1"; # even major numbers are stable
    sha256 = "01pxjdbhvpxf00ncf8d9wxc8gkcqcxz59lwrpa151ah988inxkrc";
  
    # This is for Okular (and similar) to support subpixel rendering.
    # It's kept from upstream because of political reasons.
    qtcairo_patch = fetchpatch {
      url = "https://github.com/giddie/poppler-qt4-cairo-backend/compare/"
        + "fa1d636...b30f96c.diff"; # update to current maint...qt4-lcd
      sha256 = "0g18y247k2vcz1n56rnfpy226f22v4r9c7pk8cf2h9l12vz2qxkm";
    };
  
    poppler_drv = nameSuff: merge: stdenv.mkDerivation (stdenv.lib.mergeAttrsByFuncDefaultsClean [
    rec {
  