sgl-project/sglang · error · ValueError

Hugging Face weight URL has no filename: {source!r}

Error message

Hugging Face weight URL has no filename: {source!r}

What it means

Raised when a Hugging Face URL passed to parse_weight_source resolves to a repo root with no filename component (e.g. https://huggingface.co/owner/repo with no /resolve/.../file path). The parser requires a concrete file path so it can pin an exact weight file. Without a tail the library cannot construct an unambiguous WeightSource.

Source

Thrown at python/sglang/multimodal_gen/runtime/weights/source.py:108

            revision=revision,
        )
    if action not in ("tree", "blob", "resolve") or len(raw_parts) < 4:
        raise ValueError(f"Unsupported Hugging Face weight URL: {source!r}")

    url_revision = unquote(raw_parts[3])
    selected_revision = _merge_revision(url_revision, revision)
    tail = "/".join(unquote(part) for part in raw_parts[4:])
    if action == "tree":
        subfolder = _validate_relative_hub_path(tail, "subfolder") if tail else None
        return WeightSource(
            original=source,
            kind="huggingface",
            repo_id=repo_id,
            revision=selected_revision,
            subfolder=subfolder,
        )
    if not tail:
        raise ValueError(f"Hugging Face weight URL has no filename: {source!r}")
    return WeightSource(
        original=source,
        kind="huggingface",
        repo_id=repo_id,
        revision=selected_revision,
        filename=_validate_relative_hub_path(tail, "filename"),
    )


def parse_weight_source(
    source: str,
    *,
    revision: str | None = None,
) -> WeightSource:
    """Parse local paths, Hub repo IDs, subfolders, and exact Hub URLs."""
    expanded = os.path.expanduser(source)
    parsed = urlparse(source)
    if parsed.scheme in ("http", "https"):

View on GitHub (pinned to 0132848349)

Solutions

1. Append the file path to the URL, e.g. https://huggingface.co/owner/repo/resolve/main/model.safetensors
2. If you mean the whole repo or a subfolder, pass the plain 'owner/repo' or 'owner/repo/subfolder' reference instead of a URL

Example fix

# before
parse_weight_source("https://huggingface.co/org/repo")
# after
parse_weight_source("https://huggingface.co/org/repo/resolve/main/model.safetensors")

from urllib.parse import urlparse

def hf_url_has_filename(url: str) -> bool:
    parts = [p for p in urlparse(url).path.split("/") if p]
    # expect owner/repo/(resolve|blob)/rev/file...
    return len(parts) >= 5

When it happens

Trigger: Calling parse_weight_source (or resolve_weight) with a HF URL whose path ends at the repo or subfolder level, omitting the /revision/resolve/<rev>/<path> or /blob/<rev>/<path> suffix.

Common situations: Copy-pasting a repo page URL instead of a file URL from the HF website; constructing URLs programmatically and forgetting the filename segment.

Related errors

• Invalid Hugging Face {field_name}: {path!r}
• Only huggingface.co weight URLs are supported; use a local p
• Weight URL pins revision {url_revision!r}, which conflicts w
• Diffusion weights must come from a Hugging Face model repo
• Hugging Face weight URL has no model repo: {source!r}

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/051416b46f0d3b20. Report an issue: GitHub.