Missing python import: socket in trac.web.api

[Jeroen T. Vermeulen]

Binary package hint: trac

My web server hangs up every few days since I upgraded it to lucid. One error I see in the logs is this trac bug.

Line 464 of /usr/lib/python2.6/dist-packages/trac/web/api.py references the socket module, in Request.write:

    except (IOError, socket.error), e:

The file does not import the socket module, so I get a traceback:

2010-09-05 02:13:53,373 Trac[main] ERROR: Internal Server Error:
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/trac/web/main.py", line 450, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.6/dist-packages/trac/web/main.py", line 230, in dispatch
    req.send(output, content_type or 'text/html')
  File "/usr/lib/python2.6/dist-packages/trac/web/api.py", line 358, in send
    self.write(content)
  File "/usr/lib/python2.6/dist-packages/trac/web/api.py", line 464, in write
    except (IOError, socket.error), e:
NameError: global name 'socket' is not defined

A simple "import socket" near the top of the file should fix this.

I have yet to see whether this fix stops the hangups. The hangups seem to be related to trac fcgi processes spinning forever on a lock. Sometimes I catch them merely using up all CPU. I can only guess about the times when I can no longer get into the server; the server still runs to some extent and reportedly uses all available CPU time when that happens.

[Jeroen T. Vermeulen (jtv)]

Unfortunately, fixing this does not cure the regular server hangs.

[Jeroen T. Vermeulen (jtv)]

Ah, and it wouldn't—there's a similarly missing import for errno in the same file. Used one line down from the bug I reported originally, so it's going to cause the same number of failures.

[Jeroen T. Vermeulen (jtv)]

Even with those things solved, the application still hangs up regularly. I'm beginning to suspect the spam filter plugin.