tracebacks within syslog are not using "trac" as the syslog application name

[ktyedgewall@…]

I'm running trac within Apache and mod_wsgi using daemon mode. Looking in my messages/syslog file, I found the following logged traceback:

Aug 16 10:33:57 myhost Trac[myinstance:api] WARNING: HTML preview using EnscriptRenderer failed:
Aug 16 10:33:57 myhost Traceback (most recent call last):
Aug 16 10:33:57 myhost File "/usr/local/lib/python2.6/dist-packages/Trac-0.12.3-py2.6.egg/trac/mimeview/api.py", line 766, in render
Aug 16 10:33:57 myhost rendered_content, filename, url)
Aug 16 10:33:57 myhost File "/usr/local/lib/python2.6/dist-packages/Trac-0.12.3-py2.6.egg/tracopt/mimeview/enscript.py", line 147, in render
Aug 16 10:33:57 myhost raise Exception(err)
Aug 16 10:33:57 myhost Exception: Running enscript failed with (127, sh: enscript: not found), disabling EnscriptRenderer (command: 'enscript --color -h -q --language=html -p - -Epython')

Note that only the first line has a "Trac[myinstance:api]" syslog application prefix. The following lines respectively have syslog application as "Traceback", "File", "rendered_content", "File", "raise", and "Exception". Without the correct syslog application, categorizing these log messages using log processing scripts becomes difficult.

Please either prefix all traceback messages with "Trac" so I can identify their origin programmatically, or allow me to configure tracebacks to be sent somewhere other than syslog.

How to reproduce

• configure Trac to log to syslog
• raise a Trac exception
• look in syslog for the stacktrace, which is missing "Trac" as a syslog appliction name

System information

• Ubuntu 10.04.4 (LTS/Lucid)
• Python 2.6.5 (Ubuntu package 2.6.5-1ubuntu6)
• Apache 2, using apache2-mpm-worker (Ubuntu package 2.2.14-5ubuntu8.9)
• libapache2-mod-python (Ubuntu package 3.3.1-8ubuntu2)
• libapache2-mod-wsgi (Ubuntu package 2.8-2ubuntu1)
• Trac 0.12.3 (Python egg, configured as WSGIDaemonProcess processes=2 threads=15)

[Remy Blank]

Trac is using the stock logging module from Python, and I suspect this is a bug (or a limitation) of that system.

[Christian Boos]

It's even a syslog-ng only issue, according to ​Python-issue:6444.

Look for the ​no-multi-line flags (since 3.2) and the ​indent-multi-line function (since 3.3). Maybe that could do the trick.

If this is happening with another system than syslog-ng, mentioning it on the python issue 6444 could be useful.