Description of problem:
As of the latest upstream retrace-server, if we fail to detect the kernel version we now see the following message in /var/log/httpd/error_log:
Traceback (most recent call last):
  File "/usr/bin/retrace-server-worker", line 64, in <module>
    worker.start(kernelver=kernelver, arch=cmdline.arch)
  File "/usr/lib/python2.6/site-packages/retrace/retrace_worker.py", line 910, in start
    self._fail()
  File "/usr/lib/python2.6/site-packages/retrace/retrace_worker.py", line 148, in _fail
    raise RetraceWorkerError(errorcode=errorcode)
retrace.retrace.RetraceWorkerError: None


Version-Release number of selected component (if applicable):
retrace-server-1.14-2.el6

How reproducible:
Every time

Steps to Reproduce:
1. submit a vmcore which will fail due to kernel detection (either a custom kernel, or one such as in https://bugzilla.redhat.com/show_bug.cgi?id=1149356

Actual results:
Backtrace in /var/log/httpd/error_log if we can't detect the kernel version on a vmcore


Expected results:
No backtrace but some error message indicating the kernel version detection failed (we already have this in retrace_log - maybe point there for the task?)

Additional info:
Low impact / priority.  I filed this bug as I don't think this is the intent of the error handling and it may be a good cleanup at some point.