open-mmlab/mmdetection · warning

nms_cfg in test_cfg will be deprecated. Please rename it as

Error message

nms_cfg in test_cfg will be deprecated. Please rename it as nms

What it means

CornerHead._bboxes_nms warns (note: via a buggy `warning.warn` call — it should be `warnings.warn`, so this line itself can raise NameError in some versions) when test_cfg still uses the old key `nms_cfg` instead of `nms`, then aliases cfg.nms = cfg.nms_cfg. The config key was renamed in mmdet 3.x.

Source

Thrown at mmdet/models/dense_heads/corner_head.py:834

        keepinds = (det_bboxes[:, -1] > -0.1)
        det_bboxes = det_bboxes[keepinds]
        det_labels = clses[keepinds]

        if with_nms:
            det_bboxes, det_labels = self._bboxes_nms(det_bboxes, det_labels,
                                                      self.test_cfg)

        results = InstanceData()
        results.bboxes = det_bboxes[..., :4]
        results.scores = det_bboxes[..., 4]
        results.labels = det_labels
        return results

    def _bboxes_nms(self, bboxes: Tensor, labels: Tensor,
                    cfg: ConfigDict) -> Tuple[Tensor, Tensor]:
        """bboxes nms."""
        if 'nms_cfg' in cfg:
            warning.warn('nms_cfg in test_cfg will be deprecated. '
                         'Please rename it as nms')
        if 'nms' not in cfg:
            cfg.nms = cfg.nms_cfg

        if labels.numel() > 0:
            max_num = cfg.max_per_img
            bboxes, keep = batched_nms(bboxes[:, :4], bboxes[:,
                                                             -1].contiguous(),
                                       labels, cfg.nms)
            if max_num > 0:
                bboxes = bboxes[:max_num]
                labels = labels[keep][:max_num]

        return bboxes, labels

    def _decode_heatmap(self,
                        tl_heat: Tensor,
                        br_heat: Tensor,

View on GitHub (pinned to cfd5d3a985)

Solutions

1. Rename `nms_cfg` to `nms` in the model's test_cfg in your config
2. If you hit a NameError on `warning.warn`, upgrade mmdet — the typo was fixed upstream

Example fix

# before
test_cfg=dict(nms_cfg=dict(type='nms', iou_threshold=0.5), max_per_img=100)
# after
test_cfg=dict(nms=dict(type='nms', iou_threshold=0.5), max_per_img=100)

test_cfg = cfg['model'].get('test_cfg', {})
if 'nms_cfg' in test_cfg:
    test_cfg['nms'] = test_cfg.pop('nms_cfg')  # migrate before building model

When it happens

Trigger: Running CornerNet inference with a test_cfg containing `nms_cfg=...` instead of `nms=...` (old 2.x config).

Common situations: Reusing mmdet 2.x CornerNet configs with mmdet 3.x; converting configs manually and missing the nms key rename.

Related errors

• {kernel} kernel is not supported in matrix nms!
• The `file_client_args` is deprecated, please use `backend_ar
• The annotation file of Open Images Challenge should be a txt
• Invalid text mode "{self.text_mode}".
• No sample in split "{self.split}".

AI-assisted analysis of open-mmlab/mmdetection@cfd5d3a985 (2026-08-27). Data as JSON: /api/errors/9962fdbc32452823. Report an issue: GitHub.