sgl-project/sglang · error · ValueError

Removed server argument(s): {replacements}

Error message

Removed server argument(s): {replacements}

What it means

ValueError raised by ServerArgs._reject_retired_args when kwargs contain one or more server arguments that were removed from the API. The message maps each retired name to its replacement (name -> replacement), so it doubles as a migration hint.

Source

Thrown at python/sglang/multimodal_gen/runtime/server_args/server_args.py:3137

                server_args_kwargs["kv_cache_quant_config"] = kv_quant_config
            elif attr in kwargs:
                server_args_kwargs[attr] = kwargs[attr]

        return cls(**server_args_kwargs)

    @staticmethod
    def _reject_retired_args(kwargs: dict[str, Any]) -> None:
        retired_args = {
            "decoder_tp": "decoder_sp for decoder/VAE parallel decode",
            "warmup": "warmup_mode=request or warmup_mode=off",
            "server_warmup": "warmup_mode=server or warmup_mode=off",
        }
        removed = [name for name in retired_args if name in kwargs]
        if removed:
            replacements = "; ".join(
                f"{name} -> {retired_args[name]}" for name in removed
            )
            raise ValueError(f"Removed server argument(s): {replacements}")

    @staticmethod
    def load_config_file(config_file: str) -> dict[str, Any]:
        """Load a config file."""
        if config_file.endswith(".json"):
            with open(config_file, "r") as f:
                return json.load(f)
        elif config_file.endswith((".yaml", ".yml")):
            try:
                import yaml
            except ImportError:
                raise ImportError(
                    "Please install PyYAML to use YAML config files. "
                    "`pip install pyyaml`"
                )
            with open(config_file, "r") as f:
                return yaml.safe_load(f)
        else:

View on GitHub (pinned to 0132848349)

Solutions

1. Rename each flagged argument to its replacement shown in the message (format: old -> new).
2. Delete the argument if no replacement is listed and the feature was removed.
3. Regenerate or update saved config files against the current ServerArgs fields.
4. Pin the previous library version only as a temporary stopgap while migrating.

Example fix

# before
ServerArgs.from_kwargs(chunked_prefill_size=8192)  # retired name
# after
ServerArgs.from_kwargs(max_prefill_tokens=8192)  # per message mapping

# mirror the retired check: drop/rename known-retired keys before constructing
retired = {"old_arg_name": "new_arg_name"}  # keep in sync with release notes
for k in list(kwargs):
    if k in retired:
        kwargs[retired[k]] = kwargs.pop(k)

try:
    args = ServerArgs.from_kwargs(**kwargs)
except ValueError as e:
    if "Removed server argument" in str(e):
        # parse 'old -> new' pairs from message and auto-migrate
        raise

When it happens

Trigger: Calling ServerArgs.from_kwargs / from_dict (or a config file) that still contains arguments listed in the retired_args table after an upgrade renamed or deleted them.

Common situations: Upgrading SGLang/multimodal_gen and reusing old config JSON/YAML or old launch scripts; code that programmatically builds kwargs from an outdated constants list.

Related errors

• expert cache and staging budgets, and read splits, must be p
• expert-pack stats flush interval cannot be negative
• Block sparse tensors{context} require BLOCK_SIZE_KV={base_n_
• Invalid arch format: {arch_str}
• attn_sink requires topk_length to be provided as well

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/d1b4906c63e2b652. Report an issue: GitHub.