anchor.diff:      # 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";
  +    version = "1.21.4";
  +    rev = "782ba5e5ab9476770378ec9f1901803e0d38ac41";
     };
   in
   buildBazelPackage rec {
  
positive.code:     owner = "envoyproxy";
      repo = "envoy";
      inherit (srcVer) rev;
      hash = "sha256:11mm72zmb479ss585jzqzhklyyqmdadnvr91ghzvjxc0j2a1hrr4";
  
      postFetch = ''
        chmod -R +w $out
  
negative.code: 
    fetchAttrs = {
      sha256 = {
        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;
  