anchor.diff:    docbook_xml_dtd_45 != null &&
     docbook5_xsl != null &&
     docbook_xsl != null &&
  -  fop != null &&
  +  (fop != null || !enableJava) &&
   # TODO: Package this:
   #  epubcheck != null &&
     gnused != null &&
  
positive.code:         -e "s|^ASCIIDOC =.*|ASCIIDOC = '$out/bin/asciidoc'|" \
          -e "s|^XSLTPROC =.*|XSLTPROC = '${libxslt.bin}/bin/xsltproc'|" \
          -e "s|^DBLATEX =.*|DBLATEX = '${dblatexFull}/bin/dblatex'|" \
          -e "s|^FOP =.*|FOP = '${fop}/bin/fop'|" \
          -e "s|^W3M =.*|W3M = '${w3m}/bin/w3m'|" \
          -e "s|^LYNX =.*|LYNX = '${lynx}/bin/lynx'|" \
          -e "s|^XMLLINT =.*|XMLLINT = '${libxml2.bin}/bin/xmllint'|" \
  
negative.code: # backends
  , enableDeckjsBackend ? false
  , enableOdfBackend ? false
  
  # java is problematic on some platforms, where it is unfree
  , enableJava ? true
  }:
  
  assert enableStandardFeatures ->
  