Yum is failing for me fairly spectacularly and I'm not sure if the
problem is yum or me. The error I get is:

# yum update yum
Setting up Update Process
Setting up Repos
Traceback (most recent call last):
  File "/usr/bin/yum", line 7, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 68, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 413, in doCommands
    return self.updatePkgs()
  File "/usr/share/yum-cli/cli.py", line 932, in updatePkgs
    self.doRepoSetup()
  File "/usr/share/yum-cli/cli.py", line 81, in doRepoSetup
    repo.getRepoXML(text=repo)
  File "repos.py", line 589, in getRepoXML
  File "repos.py", line 566, in get
  File "mirror.py", line 414, in urlgrab
  File "mirror.py", line 400, in _mirror_try
  File "grabber.py", line 619, in urlgrab
  File "grabber.py", line 548, in _retry
  File "grabber.py", line 605, in retryfunc
  File "grabber.py", line 728, in __init__
  File "grabber.py", line 795, in _do_open
  File "grabber.py", line 886, in _make_request
  File "/usr/lib/python2.3/urllib2.py", line 326, in open
    '_open', req)
  File "/usr/lib/python2.3/urllib2.py", line 306, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.3/urllib2.py", line 980, in file_open
    return self.open_local_file(req)
  File "/usr/lib/python2.3/urllib2.py", line 1004, in open_local_file
    if not host or \
socket.gaierror: (-2, 'Name or service not known')

My yum configuration is brand new since my old configuration suddenly
vanished on all four of my machines (I hadn't expected that!). The only
two files I have changed are:

# cat sl.repo
[main]
[sl-base]
name=SL 4 base
baseurl=file://nfs/SL/40/$basearch/SL/RPMS/
enabled=1

# cat sl-errata.repo
[main]
[sl-errata]
name=SL 4 base
baseurl=file://nfs/SL/40/$basearch/errata/SL/RPMS/
enabled=1


Any suggestions?

Thanks

John