unslothai/unsloth · warning · HTTPException

Path cannot be empty

Error message

Path cannot be empty

What it means

In the linked-folder flow, _resolve_linked_folder_path() calls folder_sync.validate_folder_path() on the granted canonical path; that function raises ValueError('Path cannot be empty') when the path is empty, whitespace-only, or contains a NUL byte. The route's generic except ValueError handler maps it to HTTP 400 with the validator's message. validate_folder_path applies the model scan-folder policy (no symlinks, must be a readable non-root, non-sensitive directory, not the uploads root).

Source

Thrown at studio/backend/routes/rag.py:295

    try:
        grant = verify(
            native_path_lease,
            operation = "link-documents",
            expected_kind = "document-folder",
            expected_path_type = "directory",
        )
        device_id = getattr(grant, "device_id", None)
        file_id = getattr(grant, "file_id", None)
        if device_id is None or file_id is None:
            raise NativePathLeaseError("Native folder grant has no stable identity.")
        return (
            folder_sync.validate_folder_path(str(grant.canonical_path)),
            (device_id, file_id),
        )
    except NativePathLeaseError as exc:
        raise HTTPException(status_code = 400, detail = str(exc)) from exc
    except ValueError as exc:
        raise HTTPException(status_code = 400, detail = str(exc)) from exc


def _folder_view(row: dict) -> dict:
    status = (
        "syncing"
        if row["status"] == "syncing"
        else "error"
        if row["status"] in {"error", "retired"}
        else "idle"
    )
    return {
        "id": row["id"],
        "displayName": row["name"],
        "scopeType": row["scope_type"],
        "scopeId": row["scope_id"],
        "status": status,
        "error": row.get("last_error"),
        "lastSyncedAt": row.get("last_scan_at"),

View on GitHub (pinned to 203007d190)

Solutions

1. Select an explicit, non-empty local directory path and re-issue the lease for it.
2. If the detail is a different validate_folder_path message, follow it: remove symlinks from the path, avoid home/root/system/credential directories, ensure read+execute permission.
3. Update the desktop bridge if canonical_path is being emitted empty.

Example fix

# before
link_folder(lease_for='            ')  # whitespace path -> 400 Path cannot be empty
# after
link_folder(lease_for='/home/user/Documents/research')  # real directory

import os
p = path.strip()
assert p and '\x00' not in p and os.path.isdir(os.path.realpath(os.path.expanduser(p))), 'pick a real directory'
assert not os.path.islink(os.path.abspath(os.path.expanduser(p))), 'symlinked folders are rejected'

const plausibleFolderPath = (p: string): boolean =>
  p.trim().length > 0 && !p.includes('\0') && !p.endsWith('/');

if (res.status === 400) { showFolderPolicyError(detail); /* detail names the exact policy violated */ }

When it happens

Trigger: Linking a folder whose resolved path is empty or whitespace after lease verification — a degenerate lease grant, or upstream code passing grant.canonical_path when it is blank. Other ValueError messages from the same validator (symlink, does not exist, not a directory, not readable, root/home/sensitive/system path, uploads-root overlap) surface through the identical handler.

Common situations: Bridge bug produces an empty canonical_path; user selects a path like '/dev/null' style specials; broader validation failures from selecting ~/.ssh, filesystem root, or the managed uploads folder itself.

Related errors

• Native folder grant has no stable identity.
• Linked folders support only knowledge-base and project scope
• Unsupported file type '{ext}'. Allowed: {sorted(config.UPLOA
• Uploaded file is empty.
• Native path grant is required.

AI-assisted analysis of unslothai/unsloth@203007d190 (2026-08-15). Data as JSON: /api/errors/7fee472767df1de1. Report an issue: GitHub.