anchor.diff:      owner = "Molcas";
       repo = "OpenMolcas";
       rev = gitLabRev;
  -    sha256 = "sha256-GMi2dsNBog+TmpmP6fhQcp6Z5Bh2LelV//MqLnvRP5c=";
  +    sha256 = "0p2xj8kgqdk5kb1jv5k77acbiqkbl2sh971jnz9p00cmbh556r6a";
     };
   
     patches = [ (fetchpatch {
  
positive.code:   "OpenMolcas requires OpenBLAS or MKL.";
  
  let
    version = "21.10-2021-10-11";
    gitLabRev = "117305462bac932106e8e3a0347238b768bcb058";
  
    python = python3.withPackages (ps : with ps; [ six pyparsing ]);
  
  
negative.code:     python
      armadillo
      chemps2
      libxc
    ];
  
    # tests are not running right now.
  