Cannot show Depgraph

[anonymous]

When I click on the Depgraph link an error occurs, with the following display:

 Trac detected an internal error:

OSError: [Errno 2] No such file or directory

and the following log:

(...)
  File "/usr/lib/python2.7/dist-packages/genshi/template/eval.py", line 178, in evaluate
    return eval(self.code, _globals, {'__data__': data})
  File "/usr/local/lib/python2.7/dist-packages/TracMasterTickets-3.0.5dev_r13319-py2.7.egg/mastertickets/templates/depgraph.html", line 32, in <Expression u"Markup(graph_render('cmapx').decode('utf8'))">
    ${Markup(graph_render('cmapx').decode('utf8'))}
  File "/usr/local/lib/python2.7/dist-packages/TracMasterTickets-3.0.5dev_r13319-py2.7.egg/mastertickets/graphviz.py", line 141, in render
    stderr=subprocess.PIPE)
  File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1259, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

Installed trac 12.5 in debian 7.3 with:

sudo apt-get install trac
sudo apt-get install trac-graphviz
sudo apt-get install trac-mastertickets

What problem could be?

[Jun Omae]

A duplicate of #11577.