unslothai/unsloth · error · ValueError

a single-file checkpoint name is required for a '{kind}' loa

Error message

a single-file checkpoint name is required for a '{kind}' load.

What it means

Raised in the cheap, network-free validation when the resolved load kind is 'gguf' or 'single_file' but no checkpoint filename was supplied. Both transformer-only paths need to know which file inside the repo (or local directory) to load; its absence fails here rather than after the resident GPU model has been evicted.

Source

Thrown at studio/backend/core/inference/diffusion.py:1676

                f"Non-GGUF diffusion loads are restricted to unsloth/* repos (or a local "
                f"path); got '{repo_id}'. Pass a gguf_filename to load a GGUF instead."
            )
        # The companion base repo also loads via from_pretrained, so it must clear the same trust bar.
        if base_repo and base_repo.strip() and not _is_trusted_diffusion_repo(base_repo):
            raise ValueError(
                f"base_repo is restricted to unsloth/* repos (or a local path); got '{base_repo}'."
            )
        # A local base_repo loads as a full pipeline; reject a non-pipeline one before eviction.
        _assert_local_base_is_pipeline(base_repo)
        # Reject a bad LOCAL pick before the route evicts chat: a path-shaped repo_id must be on disk.
        local_root = Path(repo_id).expanduser()
        # Path-shaped: "."/".." prefix, a backslash (never in "org/name"), or an absolute path.
        path_shaped = (
            repo_id.startswith(("/", "\\", "~", ".")) or "\\" in repo_id or local_root.is_absolute()
        )
        if kind in ("gguf", "single_file"):
            if not gguf_filename:
                raise ValueError(f"a single-file checkpoint name is required for a '{kind}' load.")
            # Fail a kind/extension mismatch before the handoff: gguf needs .gguf, single_file must not.
            is_gguf_name = gguf_filename.lower().endswith(".gguf")
            if kind == "gguf" and not is_gguf_name:
                raise ValueError("a 'gguf' load requires a .gguf checkpoint name.")
            if kind == "single_file" and is_gguf_name:
                raise ValueError("a .gguf checkpoint needs model_kind 'gguf', not 'single_file'.")
            # A single-file load must name a real .safetensors, else it evicts chat then fails in background.
            if kind == "single_file" and not gguf_filename.lower().endswith(".safetensors"):
                raise ValueError(
                    f"'{gguf_filename}' is not a loadable single-file checkpoint "
                    f"(expected a .safetensors name; use a .gguf name for a GGUF load)."
                )
            if local_root.exists():
                resolve_local_gguf_child(local_root, gguf_filename)
            elif path_shaped:
                raise FileNotFoundError(f"Local model path does not exist: {repo_id}")
        else:  # pipeline
            if gguf_filename:

View on GitHub (pinned to 203007d190)

Solutions

Pass the checkpoint filename: a .gguf name for a gguf load, a .safetensors name for a single_file load.
If you meant a full pipeline load, set model_kind='pipeline' (or leave unset and pass no gguf_filename).
List the repo's files (HF file tree or local dir) to get the exact filename including quant suffix.

Example fix

# before
manager.validate_load_request(repo_id="org/model", model_kind="gguf")
# ValueError: a single-file checkpoint name is required for a 'gguf' load.

# after
manager.validate_load_request(repo_id="org/model", model_kind="gguf",
                               gguf_filename="model-Q4_K_M.gguf")

Defensive patterns

Strategy: validation

Validate before calling

kind = resolve_model_kind(gguf_filename, model_kind)
if kind in ("gguf", "single_file"):
    assert gguf_filename, f"a checkpoint name is required for a '{kind}' load"

Try / catch

try:
    fam = manager.validate_load_request(repo_id=r, model_kind=k, gguf_filename=f)
except ValueError as e:
    if "checkpoint name is required" in str(e):
        prompt_for_checkpoint_file(r, k)
    else:
        raise

Prevention

Make filename a required field in any UI that offers gguf/single_file modes.
Clear gguf_filename whenever the mode switches to pipeline so stale state cannot produce kind/param mismatches.
Prefer letting gguf_filename drive kind inference rather than setting both independently.

When it happens

Trigger: Calling validate_load_request / load with model_kind='gguf' or 'single_file' (or a family/parameters combination that resolves to those kinds) with gguf_filename=None or empty.

Common situations: UI sends model_kind but drops the filename field; saved preset from a pipeline load has kind overwritten but no file picked; scripting the API and forgetting the second positional-style parameter.

Related errors

AI-assisted analysis of unslothai/unsloth@203007d190 (2026-08-15). Data as JSON: /api/errors/c09606306dfb4f3d. Report an issue: GitHub.