anchor.diff:    docbook_xsl = common {
       pname = "docbook-xsl";
       sha256 = "0s59lihif2fr7rznckxr2kfyrvkirv76r1zvidp9b5mj28p4apvj";
  +
  +    patches = [(fetchpatch {
  +      name = "potential-infinite-template-recursion.patch";
  +      url = "https://src.fedoraproject.org/cgit/rpms/docbook-style-xsl.git/"
  +          + "plain/docbook-style-xsl-non-recursive-string-subst.patch?id=bf9e5d16fd";
  +      sha256 = "1pfb468bsj3j879ip0950waih0r1s6rzfbm2p70glbz0g3903p7h";
  +      stripLen = "1";
  +    })];
  +
     };
   
     docbook_xsl_ns = common {
  
positive.code:       inherit sha256;
      };
  
      patches = [(fetchpatch {
        name = "potential-infinite-template-recursion.patch";
        url = "https://src.fedoraproject.org/cgit/rpms/docbook-style-xsl.git/"
            + "plain/docbook-style-xsl-non-recursive-string-subst.patch?id=bf9e5d16fd";
        sha256 = "1pfb468bsj3j879ip0950waih0r1s6rzfbm2p70glbz0g3903p7h";
        stripLen = "1";
      })];
  
      propagatedBuildInputs = [ findXMLCatalogs ];
  
  
negative.code: 
  let
  
    common = { pname, sha256, patches ? [] }: let self = stdenv.mkDerivation rec {
      name = "${pname}-1.79.1";
  
      src = fetchurl {
  