text: import os
  from subprocess import Popen, PIPE
  import Bcfg2.Server.Plugin
  
  # for debugging output only
  import logging
  logger = logging.getLogger('Bcfg2.Plugins.Fossil')
  
  class Fossil(Bcfg2.Server.Plugin.Plugin,
               Bcfg2.Server.Plugin.Version):
      """Fossil is a version plugin for dealing with Bcfg2 repos."""
      name = 'Fossil'
      __version__ = '$Id$'
      __author__ = 'bcfg-dev@mcs.anl.gov'
  
      def __init__(self, core, datastore):
          Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
          self.core = core
          self.datastore = datastore
  
          # path to fossil file for bcfg2 repo
          fossil_file = "%s/_FOSSIL_" % datastore
  
          # Read revision from bcfg2 repo
          if os.path.isfile(fossil_file):
              revision = self.get_revision()
          elif not os.path.isdir(datastore):
              logger.error("%s is not a directory" % datastore)
              raise Bcfg2.Server.Plugin.PluginInitError
          else:
              logger.error("%s is not a file" % fossil_file)
              raise Bcfg2.Server.Plugin.PluginInitError
  
          logger.debug("Initialized Fossil.py plugin with %(ffile)s at revision %(frev)s" \
                      % {'ffile': fossil_file, 'frev': revision})
  
      def get_revision(self):
          """Read fossil revision information for the Bcfg2 repository."""
          try:
              data = Popen("env LC_ALL=C fossil info",
                          shell=True,
                          cwd=self.datastore,
                          stdout=PIPE).stdout.readlines()
              revline = [line.split(': ')[1].strip() for line in data if \
                         line.split(': ')[0].strip() == 'checkout'][-1]
              revision = revline.split(' ')[0]
          except IndexError:
              logger.error("Failed to read fossil info; disabling fossil support")
              logger.error('''Ran command "fossil info" from directory "%s"''' % (self.datastore))
              logger.error("Got output: %s" % data)
              raise Bcfg2.Server.Plugin.PluginInitError
          return revision
  