yum is failing with 'Parsing primary.xml error: Start tag expected, '<' not found'

Issue

• yum fails to execute with the following traceback:

Traceback (most recent call last):
  File "/usr/bin/yum", line 29, in ?
    yummain.user_main(sys.argv[1:], exit_code=True)
  File "/usr/share/yum-cli/yummain.py", line 309, in user_main
    errcode = main(args)
  File "/usr/share/yum-cli/yummain.py", line 178, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 349, in doCommands
    return self.yum_cli_commands[self.basecmd].doCommand(self, self.basecmd, self.extcmds)
  File "/usr/share/yum-cli/yumcommands.py", line 781, in doCommand
    base.repos.populateSack()
  File "/usr/lib/python2.4/site-packages/yum/repos.py", line 260, in populateSack
    sack.populate(repo, mdtype, callback, cacheonly)
  File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 190, in populate
    dobj = repo_cache_function(xml, csum)
  File "/usr/lib/python2.4/site-packages/sqlitecachec.py", line 42, in getPrimary
    self.repoid))
TypeError: Parsing primary.xml error: Start tag expected, '<' not found