Comfy-Org/ComfyUI · error · ValueError

folder_name must name a subfolder of the datasets directory,

Error message

folder_name must name a subfolder of the datasets directory, e.g. 'my_dataset'.

What it means

get_dataset_save_dir resolves the requested folder inside the first configured datasets root and then rejects the degenerate case where the resolved target equals the root itself. A folder_name of '' or '.' resolves to the root, and saving a dataset 'into the root' would scatter its files among all other datasets, so the function demands a real subfolder name.

Source

Thrown at comfy_extras/nodes_dataset.py:122

                child_key = (child_st.st_dev, child_st.st_ino)
                if child_key not in seen_dirs:
                    kept_subdirs.append(name)

            subdirs[:] = kept_subdirs

    return sorted(found)


def get_dataset_save_dir(folder_name):
    """Resolve the folder to save a new dataset into, inside the default root.

    The folder is not created here; callers makedirs after validation.
    """
    root = folder_paths.get_folder_paths("datasets")[0]
    target = secure_subfolder_path(root, folder_name)
    if os.path.realpath(target) == os.path.realpath(root):
        raise ValueError("folder_name must name a subfolder of the datasets directory, e.g. 'my_dataset'.")
    return target


def get_dataset_dir(folder_name):
    """Find an existing dataset folder by relative name across all dataset roots."""
    roots = folder_paths.get_folder_paths("datasets")
    for root in roots:
        target = secure_subfolder_path(root, folder_name)
        if os.path.realpath(target) == os.path.realpath(root):
            raise ValueError("folder_name must name a subfolder of the datasets directory, e.g. 'my_dataset'.")
        if os.path.isdir(target):
            return target
    raise ValueError(f"Dataset folder {folder_name!r} not found in: {', '.join(roots)}")


VALID_VIDEO_EXTENSIONS = [".mp4", ".avi", ".mov", ".webm", ".mkv", ".flv"]

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Provide a concrete subfolder name, e.g. 'my_new_dataset'.
2. Default the widget value in the frontend or upstream logic so it is never empty.
3. Trim slashes: 'my_dataset/' is fine but '' or '.' is not.

Example fix

# before
folder_name = ""
# after
folder_name = "my_dataset"

def concrete_folder_name(name: str) -> str:
    name = (name or "").strip().strip("/")
    if not name or name == ".":
        raise ValueError("folder_name must be a subfolder name")
    return name

def is_concrete_name(name) -> bool:
    return isinstance(name, str) and name.strip().strip("/") not in ("", ".")

When it happens

Trigger: Calling the save-dir resolver with folder_name = '', '.', or any name that realpath-normalizes to the datasets root (e.g. 'sub/../' on some filesystems). Note this fires after secure_subfolder_path, so traversal names hit the earlier containment error instead.

Common situations: An empty string widget value reaching the node; string manipulation upstream that strips the folder name to nothing; users leaving the folder field blank expecting a default.

Related errors

• Dataset folder {folder_name!r} not found in: {', '.join(root
• Expected 4D image tensor, got shape {tuple(images.shape)}
• INVALID_TAG_FILTER
• Connect at least one keyframe image.
• Spreading {len(images)} images across the clip needs an expl

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/77d0936cfd5d7635. Report an issue: GitHub.