work around a cuTENSOR 1.4.0 bug
@@ -759,6 +759,10 @@ def _try_reduction_routine(
# TODO(asi1024): Support also for F-contiguous array
return None
+ if x.size == 1 and cutensor.get_version() == 10400:
+ # WAR: element-1 reduction is buggy
+ return None
+
in_arg = x
reduce_axis, out_axis = _reduction._get_axis(axis, x.ndim)
