anchor.diff:  , langObjCpp ? stdenv.targetPlatform.isDarwin
   , langGo ? false
   , profiledCompiler ? false
  +, langJit ? false
   , staticCompiler ? false
   , enableShared ? true
   , enableLTO ? true
  
positive.code:       --replace 'if (stdinc)' 'if (0)'
  
      substituteInPlace libgcc/config/t-slibgcc-darwin \
        --replace "-install_name @shlib_slibdir@/\$(SHLIB_INSTALL_NAME)" "-install_name $lib/lib/\$(SHLIB_INSTALL_NAME)"
  
      substituteInPlace libgfortran/configure \
        --replace "-install_name \\\$rpath/\\\$soname" "-install_name $lib/lib/\\\$soname"
    '';
  
    postPatch = ''
  
negative.code: 
    inherit patches;
  
    outputs = [ "out" "man" "info" ] ++ stdenv.lib.optional (!langJit) "lib";
    setOutputFlags = false;
    NIX_NO_SELF_RPATH = true;
  
  