anchor.diff:    # dependencies for torch.utils.tensorboard
     pillow, six, future, tensorflow-tensorboard, protobuf,
   
  -  utillinux, which, isPy3k }:
  +  isPy3k, pythonOlder }:
   
   assert !openMPISupport || openmpi != null;
   
  
positive.code:     click
      numpy
      pyyaml
      # the following are required for tensorboard support
      pillow six future tensorflow-tensorboard protobuf
    ] ++ lib.optionals openMPISupport [ openmpi ];
  
    checkInputs = [ hypothesis ninja psutil ];
  
  
negative.code:     repo   = "pytorch";
      rev    = "v${version}";
      fetchSubmodules = true;
      sha256 = "0hb11m5kvs4nsi5bc9ijnv6k07593p9dw40rcn33s9vspinrcjd4";
    };
  
    patches = lib.optionals stdenv.isDarwin [
      # pthreadpool added support for Grand Central Dispatch in April
      # 2020. However, this relies on functionality (DISPATCH_APPLY_AUTO)
      # that is available starting with macOS 10.13. However, our current
  