fix #5966

src/llamafactory/chat/vllm_engine.py

@@ -115,7 +115,6 @@ async def _generate(
         prompt_ids, _ = self.template.encode_oneturn(self.tokenizer, paired_messages, system, tools)
         prompt_length = len(prompt_ids)
 
-        use_beam_search: bool = self.generating_args["num_beams"] > 1
         temperature: Optional[float] = input_kwargs.pop("temperature", None)
         top_p: Optional[float] = input_kwargs.pop("top_p", None)
         top_k: Optional[float] = input_kwargs.pop("top_k", None)
@@ -126,6 +125,9 @@ async def _generate(
         max_new_tokens: Optional[int] = input_kwargs.pop("max_new_tokens", None)
         stop: Optional[Union[str, List[str]]] = input_kwargs.pop("stop", None)
 
+        if length_penalty is not None:
+            logger.warning_rank0("Length penalty is not supported by the vllm engine yet.")
+
         if "max_new_tokens" in self.generating_args:
             max_tokens = self.generating_args["max_new_tokens"]
         elif "max_length" in self.generating_args:
@@ -149,8 +151,6 @@ async def _generate(
             temperature=temperature if temperature is not None else self.generating_args["temperature"],
             top_p=(top_p if top_p is not None else self.generating_args["top_p"]) or 1.0,  # top_p must > 0
             top_k=top_k if top_k is not None else self.generating_args["top_k"],
-            use_beam_search=use_beam_search,
-            length_penalty=length_penalty if length_penalty is not None else self.generating_args["length_penalty"],
             stop=stop,
             stop_token_ids=[self.tokenizer.eos_token_id] + self.tokenizer.additional_special_tokens_ids,
             max_tokens=max_tokens,