anchor.diff:        --without-aqua
         --disable-R-framework
         OBJC="clang"
  +      CPPFLAGS="-isystem ${libcxx}/include/c++/v1"
  +      LDFLAGS="-L${libcxx}/lib"
     '' + ''
       )
       echo >>etc/Renviron.in "TCLLIBPATH=${tk}/lib"
  
positive.code: { stdenv, fetchurl, bzip2, gfortran, libX11, libXmu, libXt, libjpeg, libpng
  , libtiff, ncurses, pango, pcre, perl, readline, tcl, texLive, tk, xz, zlib
  , less, texinfo, graphviz, icu, pkgconfig, bison, imake, which, jdk, openblas
  , curl, Cocoa, Foundation, cf-private, libobjc, tzdata, fetchpatch
  , withRecommendedPackages ? true
  , enableStrictBarrier ? false
  }:
  
negative.code:     pango pcre perl readline texLive xz zlib less texinfo graphviz icu
      pkgconfig bison imake which jdk openblas curl
    ] ++ stdenv.lib.optionals (!stdenv.isDarwin) [ tcl tk ]
      ++ stdenv.lib.optionals stdenv.isDarwin [ Cocoa Foundation libobjc libcxx ];
  
    patches = [ ./no-usr-local-search-paths.patch ];
  
  