anchor.diff:      libgphoto2 libjpeg libpng librsvg libtiff openexr sqlite libxslt
       libsoup graphicsmagick json-glib openjpeg lua pugixml
       colord colord-gtk libwebp libsecret gnome3.adwaita-icon-theme
  -    osm-gps-map
  +    osm-gps-map ocl-icd
     ];
  -
  +    
     cmakeFlags = [
       "-DBUILD_USERMANUAL=False"
     ];
  
positive.code:   # the wrappers:
    preFixup = ''
      gappsWrapperArgs+=(
        --prefix LD_LIBRARY_PATH ":" "$out/lib/darktable"
      )
    '';
  
  
negative.code: , ilmbase, gtk3, intltool, lcms2, lensfun, libX11, libexif, libgphoto2, libjpeg
  , libpng, librsvg, libtiff, openexr, osm-gps-map, pkgconfig, sqlite, libxslt
  , openjpeg, lua, pugixml, colord, colord-gtk, libwebp, libsecret, gnome3
  , ocl-icd
  }:
  
  stdenv.mkDerivation rec {
  