anchor.diff:  { lib
   , mkDerivation
  -, fetchurl
   , variant ? "standalone"
   , fetchFromGitHub
   , cmake
   , pkg-config
  +, ninja
   , opencv3
   , openexr
   , graphicsmagick
  
positive.code: , curl
  , krita ? null
  , gimp ? null
  , qtbase
  , qttools
  , writeShellScript
  
negative.code: 
    cmakeFlags = [
      "-DGMIC_QT_HOST=${if variant == "standalone" then "none" else variant}"
      "-DENABLE_SYSTEM_GMIC:BOOL=ON"
    ];
  
    postPatch = ''
      patchShebangs \
        translations/filters/csv2ts.sh \
        translations/lrelease.sh
    '';
  
    postFixup = lib.optionalString (variant == "gimp") ''
      echo "wrapping $out/${gimp.targetPluginDir}/gmic_gimp_qt/gmic_gimp_qt"
      wrapQtApp "$out/${gimp.targetPluginDir}/gmic_gimp_qt/gmic_gimp_qt"
    '';
  
    meta = with lib; {
      description = variants.${variant}.description;
  