investigate why gr is None

[github-actions]

Line: 95

deepmd-kit/source/tests/pt_expt/descriptor/test_se_t_tebd.py

Lines 92 to 102 in 4e64f8b

	self.nlist,
	)
	# se_t_tebd should return gr and sw, compare only descriptor and sw for now
	# TODO: investigate why gr is None
	np.testing.assert_allclose(
	rd1.detach().cpu().numpy(),
	rd2,
	rtol=rtol,
	atol=atol,
	err_msg=err_msg,
	)