anchor.diff: -{ stdenv, fetchurl, fetchgit, fetchpatch, buildPythonPackage, python, pythonOlder,
  +{ stdenv, lib, fetchFromGitHub, fetchpatch, buildPythonPackage, python,
     cudaSupport ? false, cudatoolkit ? null, cudnn ? null, nccl ? null, magma ? null,
     mklDnnSupport ? true, useSystemNccl ? true,
     openMPISupport ? false, openmpi ? null,
  -  buildBinaries ? false,
     buildDocs ? false,
     cudaArchList ? null,
  -  fetchFromGitHub, lib, numpy, pyyaml, cffi, click, typing, cmake, hypothesis, numactl, psutil,
  +  numpy, pyyaml, cffi, click, typing, cmake, dnnl, hypothesis, numactl, psutil,
     linkFarm, symlinkJoin,
   
     # virtual pkg that consistently instantiates blas across nixpkgs
  
positive.code:     done
    '';
  
  
    # Override the (weirdly) wrong version set by default. See
    # https://github.com/NixOS/nixpkgs/pull/52437#issuecomment-449718038
    # https://github.com/pytorch/pytorch/blob/v1.0.0/setup.py#L267
  
negative.code: 
    BUILD_NAMEDTENSOR = true;
    BUILD_DOCS = buildDocs;
  
    USE_MKL = blas.implementation == "mkl";
  
    # Unlike MKL, MKLDNN is FOSS, so we enable support for it by default. Note
    # that this was renamed to dnnl and then renamed again to oneDNN upstream, but
    # pytorch still calls it by the old name mkldnn.
    USE_MKLDNN = mklDnnSupport;
    USE_MKLDNN_CBLAS = mklDnnSupport;
  
    preBuild = ''
      export MAX_JOBS=$NIX_BUILD_CORES
      ${python.interpreter} setup.py build --cmake-only
  