anchor.diff:    ];
   
     nativeBuildInputs = [ cmake python3 ];
  -  buildInputs = lib.optional (!stdenv.isDarwin && !stdenv.isFreeBSD && !stdenv.hostPlatform.isWasm) libunwind;
  +  buildInputs = lib.optional withLibunwind libunwind;
   
  -  cmakeFlags = lib.optionals (stdenv.hostPlatform.useLLVM or false) [
  +  cmakeFlags = lib.optionals standalone [
       "-DLLVM_ENABLE_LIBCXX=ON"
       "-DLIBCXXABI_USE_LLVM_UNWINDER=ON"
     ] ++ lib.optionals stdenv.hostPlatform.isWasm [
  
positive.code: { lib, stdenv, llvm_meta, cmake, python3, fetch, libcxx, libunwind, llvm, version
  , enableShared ? !stdenv.hostPlatform.isStatic
  }:
  
  stdenv.mkDerivation {
  
negative.code:         # the magic combination of necessary CMake variables
          # if you fancy a try, take a look at
          # https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/RPATH-handling
          ${stdenv.cc.targetPrefix}install_name_tool -id $out/$file $file
        done
        make install
        install -d 755 $out/include
  