anchor.diff:        CC=$(type -p cc)
         CXX=$(type -p c++)
         FC="${gfortran}/bin/gfortran" F77="${gfortran}/bin/gfortran"
  -      JAVA_HOME="${jdk}"
  +      ${stdenv.lib.optionalString javaSupport "JAVA_HOME=\"${jdk}\""}
         RANLIB=$(type -p ranlib)
         R_SHELL="${stdenv.shell}"
     '' + stdenv.lib.optionalString stdenv.isDarwin ''
  
positive.code: , curl, Cocoa, Foundation, libobjc, libcxx, tzdata
  , withRecommendedPackages ? true
  , enableStrictBarrier ? false
  }:
  
  stdenv.mkDerivation rec {
  
negative.code:   buildInputs = [
      bzip2 gfortran libX11 libXmu libXt libXt libjpeg libpng libtiff ncurses
      pango pcre perl readline texLive xz zlib less texinfo graphviz icu
      pkgconfig bison imake which openblas curl
    ] ++ stdenv.lib.optionals (!stdenv.isDarwin) [ tcl tk ]
      ++ stdenv.lib.optionals stdenv.isDarwin [ Cocoa Foundation libobjc libcxx ]
      ++ stdenv.lib.optional javaSupport jdk;
  
    patches = [ ./no-usr-local-search-paths.patch ];
  
  