anchor.diff:  , fetchpatch
   }:
   stdenv.mkDerivation rec {
  -  version = "8.4.beta2";
  +  version = "8.4.beta3";
     name = "sage-src-${version}";
   
     src = fetchFromGitHub {
       owner = "sagemath";
       repo = "sage";
       rev = version;
  -    sha256 = "1mivhk8xgdsi0xgdbvr8lxik7nmqz434fpyh93bvz50vhsqxgx9p";
  +    sha256 = "14i2a2dzgcl9wj0067kxy5k1aq4g5yp1mhckghz0qm48ygvp1a4j";
     };
   
     nixPatches = [
  
positive.code: 
    patches = nixPatches ++ packageUpgradePatches ++ [
      ./patches/known-padics-bug.patch
    ];
  
    postPatch = ''
  
negative.code:     # https://trac.sagemath.org/ticket/25260
      ./patches/numpy-1.14.3.patch
  
      # ntl upgrade
      (fetchpatch {
        name = "lcalc-c++11.patch";
  