anchor.diff:  
     src = fetchurl {
       url = "https://download.electrum.org/${version}/Electrum-${version}.tar.gz";
  -    sha256 = "sha256-2SxSTH9P380j2KaCbkXjgmQO7K2z81AG6PMA/EMggXA=";
  +    sha256 = "sha256-ucLLfqmTKO5Qpg+PnmcdQwht7cWMWJoFjQWnDecEtVs=";
     };
   
     postUnpack = ''
  
positive.code: }:
  
  let
    version = "4.2.1";
  
    libsecp256k1_name =
      if stdenv.isLinux then "libsecp256k1.so.0"
  
negative.code:     owner = "spesmilo";
      repo = "electrum";
      rev = version;
      sha256 = "sha256-bFceOu+3SLtD2eY+aSBEn13xJw7a3aVwX39QfAuqVSo=";
  
      postFetch = ''
        mv $out ./all
  