anchor.diff: -{ lib, stdenv, fetchFromGitHub, fetchpatch, perl, which
  +{ lib, stdenv, fetchFromGitHub, perl, which
   # Most packages depending on openblas expect integer width to match
   # pointer width, but some expect to use 32-bit integers always
   # (for compatibility with reference BLAS).
  
positive.code: in
  stdenv.mkDerivation rec {
    pname = "openblas";
    version = "0.3.15";
  
    outputs = [ "out" "dev" ];
  
  
negative.code:     owner = "xianyi";
      repo = "OpenBLAS";
      rev = "v${version}";
      sha256 = "11j103s851mml6kns781kha0asxjz6b6s1vbv80aq3b6g7p05pms";
    };
  
    inherit blas64;
  
  