sgl-project/sglang · error · ValueError

{field_name} is required

Error message

{field_name} is required

What it means

Thrown by parse_tcp_host_port when the provided endpoint value is None or whitespace-only. The field named by field_name is mandatory for building a valid tcp://host:port endpoint.

Source

Thrown at python/sglang/multimodal_gen/runtime/utils/common.py:125

    if len(set(parsed)) != len(parsed):
        raise ValueError(f"--gpu-ids contains duplicate GPU ids: {parsed}")
    return parsed


def parse_size(size: str) -> tuple[int | None, int | None]:
    try:
        parts = size.lower().replace(" ", "").split("x")
        if len(parts) != 2:
            raise ValueError
        return int(parts[0]), int(parts[1])
    except ValueError:
        return None, None


def parse_tcp_host_port(value: str | None, field_name: str) -> tuple[str, int]:
    if value is None or not str(value).strip():
        raise ValueError(f"{field_name} is required")

    addr = str(value).strip()
    if addr.startswith("tcp://"):
        addr = addr[len("tcp://") :]

    try:
        host, port_str = addr.rsplit(":", 1)
    except ValueError as exc:
        raise ValueError(
            f"{field_name} must be formatted as tcp://host:port or host:port"
        ) from exc

    host = host.strip()
    port_str = port_str.strip()
    if not host or not port_str:
        raise ValueError(f"{field_name} must include both host and port: {value!r}")

    try:

View on GitHub (pinned to 0132848349)

Solutions

1. Set the required endpoint field (host:port or tcp://host:port) in the config object before deriving endpoints
2. Check the env var / CLI flag that feeds this field is actually set and non-empty
3. Print/dump the config right before the call to confirm which field_name is missing

Example fix

# before
pool.result_endpoint = None
# after
pool.result_endpoint = "127.0.0.1:5555"

if not endpoint or not str(endpoint).strip():
    raise SystemExit("result endpoint is required (host:port)")

def is_set_endpoint(v) -> bool:
    return v is not None and bool(str(v).strip())

try:
    host, port = parse_tcp_host_port(cfg.endpoint, "endpoint")
except ValueError as e:
    if "is required" in str(e):
        cfg.endpoint = pick_free_port_endpoint()
    else:
        raise

When it happens

Trigger: Calling parse_tcp_host_port(None, ...) or parse_tcp_host_port(" ", ...) — e.g. derive_pool_result_endpoint receiving an unset result endpoint field from the pool config.

Common situations: Missing required config field (endpoint not set in YAML/CLI), environment variable for the ZMQ endpoint unset, or default config changed between versions making a previously-optional field required.

Understand the failure class

Background: "X is required", "must be set", "cannot be empty": the missing-required-config error family, from Vertex AI project/location to WeChat keys — this error's family across 18 libraries.

Related errors

• {field_name} must be formatted as tcp://host:port or host:po
• {field_name} must include both host and port: {value!r}
• {field_name} port must be an integer: {port_str}
• {field_name} port must be between 0 and 65535: {port}
• Invalid endpoint: must contain 'inproc' or 'tcp'

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/50557c75f13bbfb9. Report an issue: GitHub.