anchor.diff:    };
     sourceRoot = "apache-arrow-${version}/cpp";
   
  -  ARROW_JEMALLOC_URL = fetchurl {
  +  ARROW_JEMALLOC_URL = jemalloc.src;
  +
  +  ARROW_MIMALLOC_URL = fetchFromGitHub {
       # From
       # ./cpp/cmake_modules/ThirdpartyToolchain.cmake
       # ./cpp/thirdparty/versions.txt
  -    url =
  -      "https://github.com/jemalloc/jemalloc/releases/download/5.2.1/jemalloc-5.2.1.tar.bz2";
  -    hash = "sha256-NDMOXOJ2CZ4uiVDZM121qHVomkxqVnUe87HYxTf4h/Y=";
  +    owner = "microsoft";
  +    repo = "mimalloc";
  +    rev = "v1.7.2";
  +    hash = "sha256-yHupYFgC8mJuLUSpuEAfwF7l6Ue4EiuO1Q4qN4T6wWc=";
     };
   
  -  ARROW_MIMALLOC_URL = fetchurl {
  -    # From
  -    # ./cpp/cmake_modules/ThirdpartyToolchain.cmake
  -    # ./cpp/thirdparty/versions.txt
  -    url =
  -      "https://github.com/microsoft/mimalloc/archive/v1.7.2.tar.gz";
  -    hash = "sha256-sZEuNUVlpLaYQQ91g8D4OTSm27Ot5Uq33csVaTIJNr0=";
  +  ARROW_XSIMD_URL = fetchFromGitHub {
  +    owner = "xtensor-stack";
  +    repo = "xsimd";
  +    rev = "aeec9c872c8b475dedd7781336710f2dd2666cb2";
  +    hash = "sha256-vWKdJkieKhaxyAJhijXUmD7NmNvMWd79PskQojulA1w=";
     };
   
     patches = [
  
positive.code: { stdenv, lib, fetchurl, fetchFromGitHub, fixDarwinDylibNames
  , autoconf, boost, brotli, cmake, flatbuffers, gflags, glog, gtest, lz4
  , perl, python3, rapidjson, re2, snappy, thrift, tzdata , utf8proc, which
  , zlib, zstd
  , enableShared ? !stdenv.hostPlatform.isStatic
  }:
  
negative.code:     "-DCMAKE_INSTALL_RPATH=@loader_path/../lib" # needed for tools executables
    ] ++ lib.optional (!stdenv.isx86_64) "-DARROW_USE_SIMD=OFF";
  
    doInstallCheck = true;
    ARROW_TEST_DATA =
      if doInstallCheck then "${arrow-testing}/data" else null;
  