code: def bind_cli(cls, parser, group):
          
          try:
              with open("./parse_build_args.py") as f:
                  source = f.read()
          except Exception as e:
              return
  
          # detect what extra args have been added
          before_args = set(x.dest for x in parser._actions)
  
          try:
              exec source in {"parser": group}
          except Exception as e:
              print_warning("Error in ./parse_build_args.py: %s" % str(e))
  
          after_args = set(x.dest for x in parser._actions)
          extra_args = after_args - before_args
  
          # store extra args onto parser so we can get to it in self.build()
          setattr(parser, "_rezbuild_extra_args", list(extra_args))
docs: Uses a 'parse_build_args.py' file to add options, if found.