weaviate/weaviate · error

nested path %q: empty sub-property path

Error message

nested path %q: empty sub-property path

What it means

This is walkPath's loop-exit fallback. The for-loop returns on the final segment (leaf) or errors earlier, so reaching the statement after the loop means the segments slice was empty from the start — the path had only the root segment's remainder of zero sub-segments. It is a defensive guard indicating the caller passed an effectively empty sub-path.

Source

Thrown at entities/filters/nested/path.go:282

		dt := schema.DataType(np.DataType[0])
		if seg.HasIndex {
			if _, ok := schema.IsArrayType(dt); !ok {
				return nil, fmt.Errorf(
					"nested path %q: sub-property %q is of type %q — [N] indexing requires an array type",
					fullPath, seg.Name, dt)
			}
		}
		if i == len(segs)-1 {
			return np, nil
		}
		if !schema.IsNested(dt) {
			return nil, fmt.Errorf(
				"nested path %q: sub-property %q must be object or object[], got %q",
				fullPath, seg.Name, dt)
		}
		props = np.NestedProperties
	}
	return nil, fmt.Errorf("nested path %q: empty sub-property path", fullPath)
}

View on GitHub (pinned to 75aa4b6d11)

Solutions

1. Never call walkPath directly; use ResolveLeaf/ResolveLeafFromRoot which pre-validate segment count
2. Validate the path string is non-empty and contains at least root.sub before resolution
3. Treat this error as an internal invariant violation and log the full path for debugging

Example fix

// before — direct call with empty sub-segments
np, err := walkPath(rootProp.NestedProperties, nil, path)
// after — go through the public resolver
np, err := nested.ResolveLeafFromRoot(rootProp, path)

if path == "" { return fmt.Errorf("empty nested path") }
segs := nested.ParseSegments(path)
if len(segs) == 0 { return fmt.Errorf("path %q parsed to zero segments", path) }

When it happens

Trigger: Calling ResolveLeafFromRoot with a path that parses to segments such that segs[1:] passed to walkPath is empty — practically only possible via direct walkPath invocation or a degenerate/empty path string that still passes the earlier length checks.

Common situations: Almost exclusively seen from direct walkPath calls in tests or internal refactors; an empty path string slipping through upstream validation.

Related errors

• ResolveLeafFromRoot: root property is nil or has no datatype
• property %q is of type %q — [N] indexing requires an array t
• property %q has no sub-property segments
• nested path %q: sub-property %q not found
• nested path %q: sub-property %q is of type %q — [N] indexing

AI-assisted analysis of weaviate/weaviate@75aa4b6d11 (2026-09-04). Data as JSON: /api/errors/8f1b1c81f9f48841. Report an issue: GitHub.