code: def pangocairo_create_context(cr):
      
      # TODO move this to core.backend
      try:
          return PangoCairo.create_context(cr)
      except KeyError as e:
          if e.args == ('could not find foreign type Context',):
              raise ShoebotInstallError("Error creating PangoCairo missing dependency: python-gi-cairo")
          else:
              raise
docs: If python-gi-cairo is not installed, using PangoCairo.create_context
      dies with an unhelpful KeyError, check for that and output somethig
      useful.