anchor.diff:  
     fetchAttrs = {
       sha256 = {
  -      x86_64-linux = "sha256-23Z6SbKnbah/NCrdMrXhrNFFASd/8xRH3fSyIE++heA=";
  -      aarch64-linux = "sha256-dMOu0HYUIUJ+XEtctjaZZ1jGGQq+cHbay8+KwR5XqP0=";
  +      x86_64-linux = "sha256-/SA+WFHcMjk6iLwuEmuBIzy3pMhw7TThIEx292dv6IE=";
  +      aarch64-linux = "sha256-0XdeirdIP7+nKy8zZbr2uHN2RZ4ZFOJt9i/+Ow1s/W4=";
       }.${stdenv.system} or (throw "unsupported system ${stdenv.system}");
       dontUseCmakeConfigure = true;
       dontUseGnConfigure = true;
  
positive.code:     # However, the version string is more useful for end-users.
      # These are contained in a attrset of their own to make it obvious that
      # people should update both.
      version = "1.21.1";
      rev = "af50070ee60866874b0a9383daf9364e884ded22";
    };
  in
  buildBazelPackage rec {
  
negative.code:     owner = "envoyproxy";
      repo = "envoy";
      inherit (srcVer) rev;
      hash = "sha256-SthKDMQs5yNU0iouAPVsDeCPKcsBXmO9ebDwu58UQRs=";
  
      postFetch = ''
        chmod -R +w $out
  