anchor.diff:  , asciidoc, texinfo, xmlto, docbook2x, docbook_xsl, docbook_xml_dtd_45
   , libxslt, tcl, tk, makeWrapper, libiconv
   , svnSupport, subversionClient, perlLibs, smtpPerlLibs
  +, perlSupport ? true
   , guiSupport
   , withManual ? true
   , pythonSupport ? true
  
positive.code:     done
    '';
  
    buildInputs = [curl openssl zlib expat gettext cpio makeWrapper libiconv perl]
      ++ stdenv.lib.optionals withManual [ asciidoc texinfo xmlto docbook2x
           docbook_xsl docbook_xml_dtd_45 libxslt ]
      ++ stdenv.lib.optionals guiSupport [tcl tk]
  
negative.code:     "prefix=\${out}"
      "SHELL_PATH=${stdenv.shell}"
    ]
    ++ (if perlSupport then ["PERL_PATH=${perl}/bin/perl"] else ["NO_PERL=1"])
    ++ (if pythonSupport then ["PYTHON_PATH=${python}/bin/python"] else ["NO_PYTHON=1"])
    ++ stdenv.lib.optionals stdenv.isSunOS ["INSTALL=install" "NO_INET_NTOP=" "NO_INET_PTON="]
    ++ (if stdenv.isDarwin then ["NO_APPLE_COMMON_CRYPTO=1"] else ["sysconfdir=/etc/"])
  