Changing the url when the request has not been completed causes an error in mod_wsgi - broken pipe.

[nwo]

I noticed that there is a problem with mod_wsgi on Apache Debian 9. When I click on changeset to some large commit of my svn repo and without waiting for the resulting page to appear, I click on some other link. This action generates an error that saves me to the logs:

Traceback (most recent call last):, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/home/trac/www/html/trac/cgi-bin/trac.wsgi", line 31, in application, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    return dispatch_request(environ, start_request), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 581, in dispatch_request, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    return _dispatch_request(req, env, env_error), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 620, in _dispatch_request, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    send_internal_error(env, req, sys.exc_info()), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 751, in send_internal_error, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    req.send_error(exc_info, status=500, env=env, data=data), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 732, in send_error, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    exc_info), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 613, in _dispatch_request, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    dispatcher.dispatch(req), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 274, in dispatch, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    req.send(output, content_type or 'text/html'), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 693, in send, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    self.write(content), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
  File "/usr/lib/python2.7/dist-packages/trac/web/api.py", line 833, in write, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
    self._write(''.join(buf)), referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunk
IOError: Apache/mod_wsgi failed to write response data: Broken pipe, referer: http://my_url/trac/myrepo/changeset/1865/myrepo/trunkrunk

Probably trac tries to answer the original request while I have already moved to the next page and there is no one to answer. I can of course ignore such errors in the log but I do not know if this is the proper operation of the application.

[Jun Omae]

A duplicate of #12650 (fixed in 1.2.1).

You can ignore the error because the client disconnect when sending the response.