Graphviz ValueError: unsupported hash type

[jerry.yang.jin@…]

trying to use graphviz in wiki

   {{{
   #!graphviz
   digraph G {Hello->World}
   }}}

after submit page, got error:

ValueError: unsupported hash type


== Python Traceback ==
File "/root/.python-eggs/Trac-1.0-py2.6.egg-tmp/trac/wiki/templates/wiki_view.html", line 49, in <Expression u'wiki_to_html(context, text)'>
  <div id="wikipage" class="trac-content" py:content="wiki_to_html(context, text)" />
File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 1546, in format_to_html
  return HtmlFormatter(env, context, wikidom).generate(escape_newlines)
File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 1501, in generate
  escape_newlines)
File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 1244, in format
  self.handle_code_block(line, block_start_match)
File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 1134, in handle_code_block
  processed = self.code_processor.process(code_text)
File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 356, in process
  text = self.processor(text)
File "build/bdist.linux-x86_64/egg/trac/wiki/formatter.py", line 343, in _macro_processor
  text)
File "build/bdist.linux-x86_64/egg/graphviz/graphviz.py", line 313, in expand_macro
  sha_key  = hashlib.new(encoded_cmd + encoded_content).hexdigest()
File "/usr/lib64/python2.6/hashlib.py", line 101, in __hash_new
  return __get_builtin_constructor(name)(string)
File "/usr/lib64/python2.6/hashlib.py", line 80, in __get_builtin_constructor
  raise ValueError, "unsupported hash type"

== System Information: ==
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.65 Safari/537.36
|| Trac || 1.0 ||
|| Agilo || 1.3.10-PRO ||
|| Genshi || 0.7 (without speedups) ||
|| psycopg2 || 2.0.14 ||
|| pygments || 1.4 ||
|| Python || 2.6.8 (unknown, Mar 14 2013, 09:31:22) [GCC 4.6.2 20111027 (Red Hat 4.6.2-2)] ||
|| setuptools || 0.8 ||
|| subversion || 1.7.10 (r1485443) ||
|| jQuery || 1.7.2 ||

== Enabled Plugins: ==

/root/.local/lib/python2.6/site-packages/binary_agilo-1.3.10_PRO-py2.6.egg
/var/lib/trac/scrum/plugins/graphviz-0.7.5-py2.6.egg
/var/lib/trac/scrum/plugins/TestManager-1.7.1-py2.6.egg
/root/.local/lib/python2.6/site-packages/TracAccountManager-0.4.3-py2.6.egg
/var/lib/trac/scrum/plugins/TracGenericClass-1.1.5-py2.6.egg
/var/lib/trac/scrum/plugins/TracGenericWorkflow-1.0.4-py2.6.egg
/root/.local/lib/python2.6/site-packages/TracPermRedirect-3.0-py2.6.egg
/root/.local/lib/python2.6/site-packages/TracSQL-0.3-py2.6.egg
/root/.local/lib/python2.6/site-packages/TracStats-0.5-py2.6.egg
/root/.local/lib/python2.6/site-packages/TracXMLRPC-0.1-py2.6.egg

[jerry.yang.jin@…]

sorry, forgot to mention this

using standalone tracd, with stunnel for SSL