Trac and mod_wsgi errors in apache

[hiro]

I have been seing a wsgi error in apache triggering from trac:

mod_wsgi (pid=23506): Exception occurred processing WSGI script '/srv/trac.torproject.org/wsgi/trac.wsgi'.
Traceback (most recent call last):
File "/srv/trac.torproject.org/wsgi/trac.wsgi", line 9, in application
return trac.web.main.dispatch_request(environ, start_response)
File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 581, in dispatch_request
return _dispatch_request(req, env, env_error)
File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 620, in _dispatch_request
send_internal_error(env, req, sys.exc_info())
File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 751, in send_internal_error
req.send_error(exc_info, status=500, env=env, data=data)
File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 732, in send_error
 exc_info)
File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 613, in _dispatch_request
dispatcher.dispatch(req)
File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 253, in dispatch
resp = chosen_handler.process_request(req)
File "/usr/lib/python2.7/dist-packages/trac/ticket/query.py", line 994, in process_request
format, filename=filename)
File "/usr/lib/python2.7/dist-packages/trac/mimeview/api.py", line 1066, in send_converted
req.write(content)
File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 833, in write
self._write(''.join(buf))
IOError: Apache/mod_wsgi failed to write response data: Broken pipe

Investigating this as a trac error but it could be also a mod_wsgi problem in apache.