roboflow/supervision · error · ValueError

All or none of the '{name}' fields must be None

Error message

All or none of the '{name}' fields must be None

What it means

Error "All or none of the '{name}' fields must be None" thrown in roboflow/supervision.

Source

Thrown at src/supervision/detection/core.py:2484

                    compact_list.append(m)
                else:
                    dense = np.asarray(m, dtype=bool)
                    if dense.shape[1:] != image_shape:
                        raise ValueError(
                            f"Dense mask shape {dense.shape[1:]} does not match "
                            f"CompactMask image_shape {image_shape}."
                        )
                    compact_list.append(
                        CompactMask.from_dense(dense, d.xyxy, image_shape)
                    )
            return CompactMask.merge(compact_list)

        def stack_or_none(name: str) -> npt.NDArray[np.generic] | None:
            values = [getattr(d, name) for d in detections_list]
            if all(v is None for v in values):
                return None
            if any(v is None for v in values):
                raise ValueError(f"All or none of the '{name}' fields must be None")
            return cast(npt.NDArray[np.generic], np.hstack(values))

        mask = cast(npt.NDArray[np.bool_] | CompactMask | None, stack_mask_or_none())
        confidence = cast(npt.NDArray[np.floating] | None, stack_or_none("confidence"))
        class_id = cast(npt.NDArray[np.integer] | None, stack_or_none("class_id"))
        tracker_id = cast(npt.NDArray[np.integer] | None, stack_or_none("tracker_id"))

        data = merge_data([d.data for d in detections_list])

        metadata_list = [detections.metadata for detections in detections_list]
        metadata = merge_metadata(metadata_list)

        return cls(
            xyxy=xyxy,
            mask=mask,
            confidence=confidence,
            class_id=class_id,
            tracker_id=tracker_id,

View on GitHub (pinned to 7f254d9784)

Solutions

1. Make the named field consistently None or not None across all objects being merged; do not mix.
2. Populate the field on every object (or set it to None on every object) before merging.

When it happens

Trigger: Thrown at src/supervision/detection/core.py:2484 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of roboflow/supervision@7f254d9784 (2026-08-15). Data as JSON: /api/errors/9a95c4566c530de1. Report an issue: GitHub.