Build failed in Jenkins: precise-alternate-amd64_oem #739

[Jenkins Notification]

See <http://d-jenkins.ubuntu-ci:8080/job/precise-alternate-amd64_oem/739/>

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Started by upstream project "precise-alternate-amd64_default" build number 987
[EnvInject] - Loading node environment variables.
Building remotely on wazn in workspace <http://d-jenkins.ubuntu-ci:8080/job/precise-alternate-amd64_oem/ws/>
[precise-alternate-amd64_oem] $ /bin/bash /tmp/hudson8283820066483989262.sh
ln: failed to create symbolic link '/var/lib/ubuntu-server-iso-testing/isos/ubuntu-alternate/ubuntu': File exists
INFO:root:Checking/Downloading current build for variant alternate from http://cdimage.ubuntu.com/precise/daily
Traceback (most recent call last):
  File "/usr/bin/download-latest-test-iso", line 244, in <module>
    main()
  File "/usr/bin/download-latest-test-iso", line 174, in main
    fh = urllib2.urlopen(sha256sum_url)
  File "/usr/lib/python2.7/urllib2.py", line 127, in urlopen
    return _opener.open(url, data, timeout)
  File "/usr/lib/python2.7/urllib2.py", line 404, in open
    response = self._open(req, data)
  File "/usr/lib/python2.7/urllib2.py", line 422, in _open
    '_open', req)
  File "/usr/lib/python2.7/urllib2.py", line 382, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.7/urllib2.py", line 1214, in http_open
    return self.do_open(httplib.HTTPConnection, req)
  File "/usr/lib/python2.7/urllib2.py", line 1184, in do_open
    raise URLError(err)
urllib2.URLError: <urlopen error [Errno 101] Network is unreachable>
Build step 'Execute shell' marked build as failure
Archiving artifacts
Recording test results
[description-setter] Could not determine description.