docs: def build(args):
      """Build a target and its dependencies."""
  
      if len(args) != 1:
          log.error('One target required.')
          app.quit(1)
  
      target = address.new(args[0])
      log.info('Resolved target to: %s', target)
  
      try:
          bb = Butcher()
          bb.clean()
          bb.load_graph(target)
          bb.build(target)
      except (gitrepo.GitError,
              error.BrokenGraph,
              error.NoSuchTargetError) as err:
          log.fatal(err)
          app.quit(1)
      except error.OverallBuildFailure as err:
          log.fatal(err)
          log.fatal('Error list:')
          [log.fatal('  [%s]: %s', e.node, e) for e in bb.failure_log]
          app.quit(1)