anchor.diff:    };
   
     #Use this instead of stdenv to build with clang
  -  clangStdenv = if stdenv.isDarwin then stdenv else lowPrio llvmPackages.stdenv;
  +  clangStdenv = if stdenv.cc.isClang then stdenv else lowPrio llvmPackages.stdenv;
     clang-sierraHack-stdenv = overrideCC stdenv clang-sierraHack;
     libcxxStdenv = if stdenv.isDarwin then stdenv else lowPrio llvmPackages.libcxxStdenv;
   
  
positive.code:   gcc = gcc6;
    gcc-unwrapped = gcc.cc;
  
    gccStdenv = if (!stdenv.isDarwin) then stdenv else stdenv.override {
      allowedRequisites = null;
      cc = gcc;
      # Include unwrapped binaries like AS, etc. and remove libcxx/libcxxabi
      extraBuildInputs = [ stdenv.cc.cc ];
    };
  
    wrapCCMulti = cc:
  
negative.code: 
    gccMultiStdenv = overrideCC stdenv gcc_multi;
    clangMultiStdenv = overrideCC stdenv clang_multi;
    multiStdenv = if stdenv.cc.isClang then clangMultiStdenv else gccMultiStdenv;
  
    gcc_debug = lowPrio (wrapCC (gcc.cc.override {
      stripped = false;
  